Which barrows should I buy torags or guthans? Both are reasonably priced for me. In addition, since I'm looking for the RS gold barrows set, should i stop working towards a fighter torso? Also what should i do with my dragon platelegs and rune platebody?
If you're looking to purchase a barrows set, I'd suggest Veracs. The skirt and helm give the best defense for their specific positions (of the armours for the barrows) and the brassard is slightly weaker than Torag's, Guthan's and Dharok's plates. The brassard, however, Verac's provides a good prayer bonus (unlike other armours of the barrows) and is a great set special.
As I'm sure there's already Dragon Legs and you're aiming to build a fighter's torso, so what I'd recommend for your to cheap OSRS gold consider is keep those as your main armour, but keep Guthan's set to make use of its special attack as a healing mechanism.