I'd say Auto Protect, Auto Haste, Def+20% (but only if it gets added onto your def stat in game and can go above 255. otherwise leave it out), and Deathproof.

I've never used break hp limit, and while I may be sorely missing that when it comes to fighting nemesis, I feel fine the way things lie now.

I don't have anyone with ultimate armors though. Yuna has one with auto haste, auron has one with autoprotect, and rikku wears whatever. it's just not quite very important (and not to mention a pain to customize)