Yeah, If you look for a Timid Gardevoir, and you want to use it defensively, you should've looked for Bold. (or relaxed if you run Trick Room, for whatever reason)
I think you need to decide move-set first, because it is much easier to Make Nature to fit moveset than moveset fit Nature; it also helps the Pokemon fit your play-style. And it is also much easier in game to do this as well (I know from experience).
I feel that this question is less objective without a move-set (People can easily argue Adamant or any other nature because there are no moves that say what is a good nature in Particular, and the no moveset question rule) :P