There is a shaker kit if you want that look but as far as HP gains you won't see it. If you don't already have a cold air kit get that instead. If you insist March makes one.
It might net you 5-10hp I'd hazard to guess. For what you'll spend you'd be much better off with other bolt-ons. Have you done the PI swap? That would really wake your car up along with gears and a tune.
Power improvment(PI). This would be swapping your Heads, cams, and intake to those from the 99-2004 model 2V. it can be done rather cheap and yields some very nice gains and your car would make more power than a 99-04 GT with similiar mods. I have the intake and cams and can tell you its well worth it. Also do all the basic bolt ons and a set of gears and you will be golden. you would have a fun car that can hold its own on the streets.