Armor mixing and stats

So I've finally hit 80, and I'm starting to plan out what armor I want to get. As opposed to going for a full set, I'd like to try to mix-and-match some dungeon armors (and maybe karma armor). However, I'm running into the "issue" that not all the dungeon armors have all of the stat spreads available.

I guess my question is has anyone else attempted something like this, and how do you typically choose the stats you want? For example, I'm a warrior, so I might just go for as many Power/Toughness/Vit sets as I can, then prioritize crit damage or crit chance; does this seem reasonable? I also primarly play PvE, although I'd like to be able to dabble in WvWvW.