Your GTX would look nice lowered.
Are you looking for a specific kit or just a hook up on a kit?
Off topic:
Here is pics of my buddy Colin's Pontiac Grand Prix GTP.
Has 20" Rims, Pacesetter exhaust, smaller S/C pulley, ram-air, bluish/black pearl paint.
12" MOJO, 2500W Memphis amp, 300A alt.
I think he said he raised it to acomadate for the 20" wheels.
Nice car...