what kind of bodykit? and where are you located, powerflow and longlife do good stainless exhausts, they'll make it to fit your car, as to buying a retro fitting one, for bodykits i dont know. theres www.stxstyling.co.uk and rieger kits aswell, the rieger RS kits aren't too bad tbh

although i'd never have one
 
the best body kit i can recommend to you is facelift bumpers, that it all.

Oh, and dont get a ghey looking exhaust - hidden TDi style or twin round, nothing silly looking.