Oh this is d2r, i don't play that so i can't answer about the attack speed buff. Most likely it works on the basis on before you add any attack speed. So most likely you would need less attack speed.
The attack speed tables are complex:
0 12/9/17 1.97
4 11/9/16 2.08
9 11/8/15 2.2
13 10/8/15 2.27
16 10/8/14 2.34
24 9/7/13 2.58
37 9/7/12 2.67
46 8/7/12 2.77
54 8/6/11 3
80 8/6/10 3.12
83 7/6/10 3.26
125 7/5/9 3.57
168 6/5/9 3.75
208 6/5/8 3.94
And since i don't quite understand the +100% ias bonus, i can't answer how much ias you would need. However, having the highest ias amount can be detrimental if you sacrifice gear pieces that has other valuable modifiers. So you can switch a few gear pieces if you want and play around with it to see what works best, and find the ias breakpoints you are comfortable with.
Anything immediately wrong with this? D2 and d2r cross checking can be done.
Helmet: Kira's guardian, with desired jewel or rune. Um rune gives +15 all resists. A jewel with 15% all resist can have another modifier, but obviously cost more.
Armor: Merc: Treachery, you: Fortitude. You swap armor with merc so that you get fade precast, then swap armors back when it is active. This way both you and your merc gets the level 15 chilling armor bonus too.
Weapon: Ebotd war pike or matriarchal pike: While war pike does about 15% more average damage, The latter can have +3 javelin skills, which means +30% damage and attack rating, which does not amount to much. But another difference is that it requires more dexterity than strength, and while breath of the dying have -60% to requirements, that extra dexterity means more damage. I also don't know if class specific weapons can be ethereal, i don't think so, so if not, war pike is the obvious choice since botd gives indestructible.
There is one other hidden weapon choice; The ethereal upgraded hone sundan is a beast of a weapon. It does not have all the defensive and special bonuses that breath of the dying have, but the 45% crushing blow is something that really helps to bring down monster hit points fast, especially against bosses. The socket slots can be utilized as you see fit, either with a perfect skull for dual leech, damage jewels, or eth rune for -25% target defense.
Gloves: This is where there are different opinions. Dracul's grasp is an obvious choice. Life tap makes you leech life from all types of monsters, including undead. This also means you have to abandon the benefits of possibly decrepify from merc's reaper's toll, or amplify damage from your own possible atma's scarab. It is the safe choice to use dracul's. If you feel like experimenting, you can use laying of hands to increase damage against demon monsters which are most monsters, including bosses. This way you can also get the earlier mentioned bonuses. Decrepified monsters are very much easier to deal with, so that is also something to consider. This is about personal preference and you would have to make your own choice. Steelrend could be an option, but it has insanely high strength requirement, which would lose you about 300 hit points or 100% damage from the loss of 100 vitality or dexterity. So it is a long shot to use those, but they do have strong modifiers. Test them out if you feel like it.
Belt: String of ears or verdungo's. String of ears gives a good 10-15 mdr bonus, while verdungo gives 120 extra hit points. Again, a choice of preference. Thundergod's vigor is an option when venturing into areas where there are black souls, or against diablo and mephisto.
Boots: It is a toss up between war travelers and gore riders. The 15% crushing blow has better effect with the melee zon than ranged, working at a 1/4 current hit point reduction instead of 1/8 at ranged. Has great effect against bosses. But you do lose out a little bit of damage and magic find%. Choice of preference.
Amulet: Atma's scarab if you choose not to use dracul's grasp. Cat's eye speeds up everything while giving some defense which is boosted by chilling armor. Metalgrid is an overlooked option which gives strong defensive properties including all resist, and a good attack rating boost too.
Ring 1: Since you have cannot be frozen on your helmet, a good choice here is wisp projector, where you can use the oak sage charges to increase hit points, or heart of wolverine to increase damage and attack rating if you want to. The lightning absorb bonus is nice to have.
Ring 2: Here is the option where you can choose freely. A really good rare ring may be the best option. Botd have mana leech and dracul's gives life leech. If you choose not to use dracul's, life leech would be a must in this ring slot. Dwarf star with it's hard point mdr, combined with possible string of ears' mdr, gives a very strong possible 30 magic damage reduction overall.
Kira's guardian gives possibly 85 all resist. Fortitude: 25-35. Preboost fade: 65. If you choose to use metalgrid: 25-35. That is a maximum of 220, enough for max resists in hell mode. This means you would have to kite boss packs with conviction aura. Overstacking with charms may be a good option.
When it comes to charms, faster run walk, life, and resists are the obvious choices. The biggest difficulty and hazard with this build is low hit points, so stacking hit point charms is a good idea. Gheed's charm to boost magic find is a good thing too.
Switch: I hate to use it myself, but on this kind of build, call to arms is the obvious choice.
Precast: Fade from treachery can be precast in the fire pylons by Hadriel by river of flame waypoints. You can always just switch and play regularly until fade triggers naturally, but that means you are fighting weakened and must take extra care until it activates.
Enchant from demon limb: The level 23 enchant from demon limb gives a 218% attack rating boost which would be stupid to leave out. Both for you and your merc. Only thing is, it has 132 strength requirement .. which can be lowered by a socket and hel rune. The charge lasts for about 12 minutes, so having a 3 socket helmet and possibly armor with 3 x perfect amethysts can worth to keep in the cube to reach the strength requirement.
Merc: Armor choices has been discussed. Guillaume's face is a good helmet option. If you choose not to use reaper's toll, there is pride runeword which boosts damage vastly for you and the merc. Might aura merc is the obvious choice. If you find that defense is lacking, you can try to use defiance and see if that makes a difference. A 10% lowered chance to be hit can make a difference.
Make of this what you want ^^ I have tried a similar setup in hardcore hell, and it is not as if you can close your eyes and plow through everything. You have about 2000-25000 hit points at most, and that is not a lot. You will have to kite more than occasionally. But if you don't mind doing that, and also manage to know how to position yourself around your merc and your max level valkyrie, you will have a lot of fun with it. Having your hit point base deplete and refill by 30-50% in the matter of seconds, and relying on reading the game well enough so that you don't get overwhelmed, is a really adrenaline-heightening experience ^^ Much more action-filled than being a regular bowazon ^^
D2