Exhaust wise, I got a 2.5 Cat-back, no resonators, mandrel bent up to the end, where there is a sport muffler. Like stated above, top end increased quite a bit. You will be surprised how much opening up these engines helps.
And people still put cams on N/Ts.
200 sounds like a bit too much on a N/T 4G63. Simple mods like an intake, full exhaust, balance shaft free, and no A/C if you want will help, but no 200. It will just make it peppier.
Not sure about the auto thing though. I have driven a few cars, same models, but one auto and one manual, and I have found that autos are a bit more sluggish. Never driven an auto DSM though, so I wouldn't know for sure.