No armor at all? Well, certainly get a basic set of rune platebody, legs, and berserker helm, and a rune defender if you haven't got one. Then, for more advanced killing, try Torag's plate and legs, or Dharok's if you want to train strength. Rune or dragon boots are nice, as well as an obsidian cape. Certainly buy a black mask if you want to train slayer, it helps loads.