depends on the way you want to play really...the real answer should be cortina for all 3 classes, if you upgrade it to level 2 there's really nothing else you need except maybe summer spirit set (which you can't get right now)
some people use Wilson CLOTHES in attack (the mount set is trash)...i'm not sure how good it is but yeah...it probably creates the illusion of hitting as a tank in attack
also the carribbean set is supposedly the best in attack but it's not auctionable and there's also currently no way to get it
for premium worker i guess going for damage is also a good variant but it's not as good as a dueler...that would involve buying murrieta horse set, captain clothes for attack and phoebe clothes in defense (murrieta clothes work as well but the leadership is low and significantly reduce your chance to hit)...and any weapons like murrieta, phoebe, lucille...........no other weapons come to mind right now. I would personally choose the phoebe ones for personal reasons\
oh, forgot to mention...ron clothes work as well instead of phoebe, much better chance to hit but less leadership (damage)