keep it stock and save yourself the headache.....
sorry i'm a pessimist right now.
EDIT: as far as actually being helpful, i would recommend making sure certain things are taken care of before you get to actual performance modding. Swap out all the vac lines, or at least the small ones off your intake mani and to your BPV and wastegate, with high quality silicone lines. Get a boost gauge and a WIDEBAND a/f gauge so you can know whats going on with your car. Get some motor mounts. Make sure your wastegate actuator isn't torn. You might also consider welding your LSD since they are ticking time bombs. You could leave it and it could last you till 100,000+ miles, or it could go tomorrow (i'm still having luck, not welded and still working). Right now i'm really wishing someone had suggested i do all this stuff before intake exhuast and whatnot. Once you get to performance modding, exhuast is a great first step. Intake prolly won't add much, but its a bolt on part and most people have one, if only for the extra noise, lol. Then the stock interwarmer has to go, theres plenty of debate on SMIC vs FMIC, do some searching and read up on what would be best for your goals with the car. After that prolly comes some sort of EMS and with that some boost control.... i'm not really gonna voice any opinions on whats best to go with for that, as i currently am trying to figure out what i'm going to do myself when it comes to that.