Use EE weapon
Use EE armor
Use Stat Charm
Win!
Vita is fun to play around with but the lack of EE weapon damage can be pretty pitiful and sometimes a burden. If you have a group capable of high damage output, go for it, but if not, I would just stick with using an EE armor, stat a bit of vita of course, then go for EE weapon and boost your damage as well.
I have tested it a few ways on SC, and would always prefer more damage than someone with an insane amount of HP. If you were farming Ambush or something risky, this could be different.
Good luck!