For spellcasters, makes sure to take combat casting, point blank shot and precise shot feats. Combat casting helps with concentration check to avoid attack of opportunity when melee casting and precise shot remove the -4 penalty for "ranged attack in combat".
There is also a teamwork feat that improve concentration further if I remember properly.
3 feats just so you can cast spells in melee combat? Not sure how you can spare so many feats. The only spellcaster that should be getting down and dirty is the magus. You are pretty much ruling out spell perfection which is the best feat in the game for most spell casters.