Which vendor in what difficulty should I look for this?

For the 40 Life Spawn on helm, the Helm iLvL must be at least at 68. You need to be lvl63 for be able to shop iLvL 68.

So, any Shop in Hell would be able to Sell it. And, Act 2, 3, 4 and 5 in NM might be able to sell it also.

You can also Gamble it.

This post was edited by RenTed on Aug 17 2015 09:22pm

iLvl 79 is required for your Great helm to spawn. Use char level at least 74 to shop it.
Fara (Nightmare), Asheara (Nightmare), Charsi (Hell), Gheed (Hell), Elzix (Hell), Gheed (Hell), Fara (Hell), Asheara (Hell) may sell that kind of helm.

I dont know where you get your ilvl79...

But if you take a look,
Here: http://classic.battle.net/diablo2exp/items/magic/pre.shtml

Artisan's > Add 3 Sockets > Body Armor(33), Helms(33), Shields(33), Weapons(33)

You need iLvL of 33 for get 3os on Magical Helm.

Here: http://classic.battle.net/diablo2exp/items/magic/suf.shtml

Mammoth > +31-40 to Life > Amulets(25), Body Armor(25), Belts(25), Barb Helms(25), Circlets(25), Dru Pelts(59), Shields(59), Clubs(68), Hammers(68), Helms(68), Maces(68), Rings(68)

You need iLvL of 68 for get 31-40 Life on Rare/Magical Helms.


So a helm with a ilvl68 or higher can spawn with both 3os and 40 Life.

This post was edited by RenTed on Aug 18 2015 12:17am

of The Mammoth alvl = 68
great helm qlvl = 23

alvl = max{ilvl,qlvl} - int(qlvl/2)
68 = max(ilvl,23) - int(23/2)
68 = ilvl - 11
79 = ilvl

/e when it comes to stuff like this, if you are lucky enough to have feanur answer your question its pretty safe to assume he knows what he is talking about

This post was edited by bonnerf2 on Aug 18 2015 03:29am