Well you have the SE model w/ the ga16 engine so you are never going to have a beast of a car so I would ask yourself whether performance or show is most important. Judging from what you have already done w/ your car you may just simply stick w/ some minor bolt-on mods. and continue w/ the cosmetic side.
-----Oh boy here comes the attacks----Yes you can get respectful gains from the ga16 and am no way bashing the SE boys(but serious hp requires no2 or turbo). I'm also aware that an sr20de w/o serious mods. isn't a monster either.
If you do decide to get some performance upgrades, begin w/ the intake/header/exhaust (in that order). They will give you a nice gain plus they are relatively easy to install.