best of luck finding one, you should not find one with rust as most are cherished. if it is mint expect to find some history of paint ( front end, wheel arches are prone to chips ) but don't let it put you off. my car has been completely repainted ( but that's cos I'm fussy and black is hard to blend !!!
these don't generally rust, but check the battery tray and round where the body kit fits. ( check the water drain on the rear spoiler / sills work and the rear post of the upper spoiler for cracks )
buy the best you can afford and get some one who knows these cars well... ( there's plenty poor examples out there but most are cherished ones )
getting a std one is now hard, most will be at 300 ish bhp or stage 1 ( 270 ish ) this is not a prob as the cars are sooo over engineered to start. just make sure it has full history inc any mods if you go that way..
best of luck fella....