Theres no reason to not talk about '04s..... if people don't mention it dont worry or take it to heart, its identical to the 2003 model. I'm not sure about any special badges, but everything about your car is the same as the '03 model. You can definitely put a supercharger on it, thats actually one of the most common modifications for the '99-04 Mustang GT's. The first thing you should do to the car would be weld in sub frame connectors, then install a 2.5" catalytic-back exhaust, K+N airfilter, and some lowering springs. After that I'd upgrade the fuel pump to a 255lph intank unit by Walbro. I love white 99+ GT's...... personally, I enjoy them even more with the Mach 1 grille delete kit and Mach 1 chin spoiler!
SS