I will explain a few setups here, with their pros and cons, and for all budgets 
I will also try to explain the reason behind each choice of item or sock so that you guys can make your own build after reading the guide.
There exists lots of way to build a BvB, you have to chose the build corresponding to your gameplay, but I won’t list them all here, I’ll give 4 builds.
While reading the guide you should listen to that : First of all a few basics:+1 vita point gives 10 life (after bo)
+1 bo gives 80 life
+1 str = +1% ed
+20 life in inventory gives roughly +50 life after bo
+20 ar gives roughly +110 ar on screen (after all bonuses of your gear are applied, note that it may be bit less if you use arre or arre 08 and more if you use a visionary helm)
+1 shout = +1 iron skin = 250-350 def (depends on level and gear, but consider an average +300 def)
+1 Max dmg (using grief) will bring +8 or 9 max dmg on screen.
Open wounds formula: http://classic.battle.net/diablo2exp/items/magic.shtml#sma
Remember: 25% damage vs player targets.
(take some time to read the cb and deadly strike formulas too)
Chance to hit formula = 2 * atlvl / (atlvl + dflvl) * AR / (AR + Defense) ;multiply by 100 to get CtH in %
Do not forget to divide by 4 to get the real CtH since the opponent usually has 75% block.
There is no need for fhr on a BvB, so don’t care about it.
Minimum ias required on a Berserker Axe to hit the last ww ias bp : 34
Minimum ias required on a Colossus Blade to hit the last ww ias bp : 39I) How to skill a BvB?On the contrary to builds, there aren’t that many ways to skill a BvB (though on some defense builds people may prefer to max iron skin before weapon mastery or WW, but this isn’t a pretty good idea…)
Here is the main one (and most effective): 20 Whirlwind
20 Weapon Mastery (sword or axe, depends on your build)
20 battle order
20 shout
1 battle command
1 natural res (always useful since a lot of barbs use psn)
1 increase speed (some say it is useless, but being able to dodge an attack and surprise your opponent is worth it)
XX iron skin (dump the rest of your points in here, you should max iron skin @ lvl 99 if you follow that skill placement)
II) How to stat a BvB?No big deal, this is a pretty obvious part ^^
Strength: enough to wear all your gear and to be able to pick up your corpse without losing items (sounds stupid but I’ve seen so many ppl crying about losing their items that I had to write it^^)
Dexterity: enough to achieve max block (75% for those having a doubt ^^).
Vitality: once you statted strength and dexterity, dump all the remaining points in it
Energy: umad ?_? NOTHING
III) The inventoryOn EVERY build use (if possible^^) a 20 stats annihilus and a 20 stats torch.I also recommend to use 1 x life/cold dmg (or max/ar/cold dmg) sc in order to slow your opponent.
Optional : 1 x 20 life/175 dmg psn sc (psn will not damage your opponent a lot, but here it is rather used as a way to annoy your opponent and see when you hit). More poison than that is useless since if you lame the guy will just use antidotes and you’ll be fucked, and it’s considered pretty bm .
For the rest of the inventory the decision is yours, there exists NO best inventory, it has to fit your needs. Here’s a list of the possible charms and their possible use.
Max ar lifers:
Gc : maximum = 10/76/45 -->Will be mainly used to boost your damages and ar.
Lc: maximum = 6/48/35 
an alternative to gc’s, provides more life, same ar but less damage
Sc: maximum= 3/20/20 the most commonly used charm, since it provides a nice life, a correct dmg and ar bonus.
Considering the final effect of those, go back to the top to calculate them yourself depending on the charms you have or you can afford.
Ar/lifers:
Gc’s: maximum = 132/45 when you really lack ar, but not that the dmg loss compared to max ar lifers is pretty important.
Sc’s: maximum = 36/20 provides more life than a gc but less ar.IMPORTANT: There is NO ultimate inventory, the best inventory will be the one fitting your build and that allows you to reach the results you want. Pay attention to making a “logical” inventory! (Which means for example don’t use a full ar/lifers inventory on a Titan barb on which you want damages^^)
IV) 4 Builds
Note for the 2nd slot (war cries)
Use either 2 x 3 wc weapon (+6 bo +6 shout) or 1 x 3wc weapon + cta 3 or more (+7 bo +4 shout)
In 1st option you have 600 more def but 80 less life than in the second. This is up to you to decide what you use, depending on your build and preferences.
Jewelry : Angelic rings + amu (+10 dex bonus from set and a HUGE amount of ar , some life and replenish life, what else ?) This is valid for EVERY build
There is a debate on using sword or axes. I would say that if you play on Europe and can afford a bug fury and a Grief Cb, then go for sword, it has so much more style and allows you to counter lamers more easily (bug fury ^^). Else just go for ba, it requires less str and it’s easier to find (and cheaper)
A) The Defense buildThe name is quite obvious; here the aim is to focus on building a tank with a huge def.
This kind of BvB is pretty effective versus Titan build since Titan barbs have usually a pretty low ar and their chance to hit you will be pretty low. However note than a very high defense will only lower your chances to be hit by little, and you will have a pretty average life and low damages)
Helm : Eth upgraded arreat Zoded
Armor : here we have 3 main choices (by order of preference)
Fortitude in sacred armor (300 ed, high def, nice life bonus)
Eth upgraded toothrow Zoded : High def and 40% ow (it is a nice armor, but as I consider playing mass ow being gay, I don’t really recommend it, though it is useful
Eth Prudence (very very high def, but it’s pretty much all that it has to offer)
Boots : Upgraded gores (there is NO alternative)
Gloves : Steelrends (mass def, nice damage add)
Weapon : Grief Berserker Axe/Colossus Blade (again, grief is THE weapon, there is no possible comparison with other available weapons, this is just the best)
Shield : Storm
Concerning storm’s sock, the optimal sock here would be a 30 ed 9 str 9 dex adds jewel. This saves some dex points, and you will need the strength to save some points too to wear your gear since it has high strength requirements.
Belt : bug belt for Europe (and rich ppl) , Verdungo for the others
Recommended inventory: max/ar/life sc’s
B ) The Titan build
THIS IS SPARTAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA (yarly)
That barb’s aim is to hit like a truck (or like Chuck Norris roundhouse kick), but you will have a rather low def, life and ar. (but the damages done by such a build are really impressive)
That kind of barb is pretty effective vs barbs with a pretty low def (which is a vast majority^^) but it is hard to play because it has a rather low life compared to others.
Helm : Arreat 08 socked 30 max jwl (remember we want damages)
Armor : Fortitude Archon Plate (here forti is the only choice, and Ap provides the best amount of def for a pretty low strength requirement)
Boots : Upgraded gore
Gloves : Steelrends (stronk gloves = stronk hits ké ?)
Weapon : Grief (remember, that’s the omfgwtfbbq weapon for a bvb)
Shield : Storm , sock it with a 30 max dmg jwl (for ppl who have Alzheimer: WE WANT DMG !!)
Belt : bug belt for Europe (and rich ppl) , Verdungo for the others
Recommended inventory: Max/ar/life gc’s + sc’s (9 x gc’s and rest sc’s)
C) The cookie buildThis is the most commonly used build, it doesn’t mean that it is bad or whatever, it works well and this is why nearly everybody uses it ^^ (but this is not my favorite anyway)
On such a build you will have a pretty balanced barb, which is basically what everybody should look for. Not that the Defense or Titan builds are bad, but they are less effective generally speaking, especially for people who have no experience with BvB.
Helm : arreat (non upped non eth, you can use a zodbug one if you’re rich ^^) socked 30 ed 9 str 9 dex adds (the aim of that sock is to save points to wear your gear and to get max block)
Armor : here we have 2 main choicesFortitude Archon Plate (once again, forti ap = high def for pretty low req, and 300% ed, it’s all we want ^^)Eth upg Toothrow (pretty nice def, and 40% ow is always nice)
The choice is yours, but I’d rather use forti. (personal choice)
Boots: Upgraded gore
Weapon: Here we have 2 choices again:Grief (blabla mass dmg)Fury (66% ow, 33% deadly, nice damages… though do not use it always, this is pretty lame and not rly appreciated when ppl play hit’n run and count on ow to win.)
Gloves : again 2 choices :Steelrends (mass dmg and def, but will require you to invest some more points in strength, though it’s not a big loss, str = dmg)Drakul’s grasp (low str reqs, 15 str to help you wear your gear, and above all 25% ow ! can be considered lame)
Shield: Storm
This time the socketing part is more tricky : if you use drakuls then sock it with a 30 ed 9 dex – req jewel, in order to save some str. (considering you use a berserker axe, if you use a Cb then use the 2nd option). The second option, for people using steelrends (and / or a Colossus blade) is to sock with a 30 ed 9 dex +xx ar (and maybe + str) jewel. The reason is quite obvious, you don’t need – req and an extra ar bonus is always welcome ^^
Belt : bug belt for Europe (and rich ppl) , Verdungo for the others
Recommended inventory: max/ar/life sc’s (add up to 1/3 of inventory in ar lifers if you got difficulties to hit)
D) The Visionary build
The aim of this build is to achieve a high ar and life but to keep as well nice def and dmg (the aim is to get similar def and dmg than the cookie but with a better life and a better ar)
The whole gear part is similar to the “cookie” build on the exception of 2 things: the helm and the socket of storm.
The 2 helm possibilities :2 barb 3 bo visio adds : in a barb specific helm, with a high defense, and if possible the following bonuses : +x to iron skin / natural res (saves 1 point) / weapon mastery (VERY VERY rare spawn) / shout ; base life ; 2 socks (but 1 sock is ok ^^)
Such a helm allows you to have a nice life and a nice def bonus. Sock it with a ed/ar/str/dex jewel if possible, all these mods are useful.
2 barb visio xx str xx dex circlet : Needs to have lot of base stats (i recommend 40+) to compete effectively with the 5 bo visio, but if you have one with 40+ base stats (in str + dex) it will allow you to save shitloads points that you will reinvest in life. Sock it with a ed/ar/str/dex jewel if possible, all these mods are useful.
Concerning storm : the socket depends on your gloves and your weapon
If you use drakul as gloves : ed/dex/-req + adds (like ar) jewel
But in this case you have to use a Berserker Axe since you will never have enough str to use a Cb or a balrog blade.
If you use steelrends as gloves : ed/str/dex/ar jewel
You can as well sock storm with a 30 max jewel or a 15 max 100 ar jewel if you want a push in dmg or in dmg and ar. The choice is yours.
Recommended inventory : Max/ar/life sc's , note that you can also add some max ar life gc's or some ar/lifers if you really want a fat ar
Remember that this guide is just my personal opinion, so feel free to ask, to debate and to react 
I hope you had as much pleasure reading the guide as I had writing it!!