The ages-old question surfaces again. Don't worry, you're not the first, and you won't be the last
I'll answer the exhaust first. You can do a custom exhaust yourself, or wait for Hector (99bonnevilleSE) at www.angryducktofuracing.com
I'd advise waiting to see what he comes up with. Nobody makes a bolt-on exhaust, but he'* working on it, and custom headers, too.
No, you can't just pop a supercharger on the top end, at least if you're thinking taking an OEM off of a SC Bonneville or Grand Prix. Partial list of things that are different between your car and mine: Heads, compression ratio, fuel rail, injectors, lower intake, engine wiring harness, pcm, and transaxle. You can put an aftermarket unit (www.zzperformance.com
), but by the time you spend that much money, you could combine it with what you could sell your car for, and buy a newer SSEi. Or just mod the hell out of your NA for the same money, like turtle_sse or Complinitor.
I'll post an article up in Techinfo on this subject.