Again, like i said, you will ALWAYS need str, nomatter the ws. Str is a primary modifier for EVERY single ws out there. And by primary modifier it doesnt mean its the first mentioned in Str10%, vit10%. Primary modifier is what is called fSTR and it is function of difference between your STR and target's VIT. This modifier is always there, and isnt changed by the fact that the secondary modifiers are str10% and vit10% wich agreably is pure shit. Nonetheless, you still need str for your fSTR. So, ill repeat myself again, you will want to get a decent amount of str with gear that offers other stats aswell. I'm not gonna list suggestions again.
As for whoever said vit stacking was better and used Genbu's kabuto as an example, thats a pretty poor example. Point by point, vit will never give better results then str, due to the fact that (yes im gonna say it again) str is BOTH a primary and a secondary modifier. However, if you are able to disregard the need of the accuracy that shura head offers, Genbus Kabuto can come out on top of shura head. This doesnt mean that vit stacking in general is a good idea.