Yowsa, so many answers.
So, I have almost decided and the RP flavour will be the ultimate deciding factor for me. Second Wind is a given in all barb builds for me. I
It will either be a Mage Slayer or Furyshaper. Berserker is nice and all, but I love the concept of reliable Carnage and hate the dependency of specific items to counter that. Also the -5 int hurts the AOE. OFC I could always RP him as a svef-eating berserker-druggie.
Constentin point out that healing is a minor issue for Mage Slayer. I get the impression Mage Slayer needs to be a more mobile barb than the other subclasses. Get in to kill mages. Get out when you're being swarmed and low on health with no reliable healing ready. And as Elric points out, paladin'y things aren't spells, so I might bring Pallegina or those items.
Hmm, Mage Slayer is looking more viable. And goddamm I hate those enemy spellcasters.