Replying to Calling all Audi fans and nerds

I am more than likely about to snag a black 2004 Audi S4 with 51,000miles (!!!!)

The car has the stock rims which, to me, need to be replaced. I am also looking to get halogen bulbs and to replace the yellow turning signal but not make the headlights all euro-based and chromed out. I am probably going to hold off on any exhaust or engine performances and not sure if I will even get to that stage. Where are the best online places to look for parts/rims/etc.. I know a lot fo you guys have some BS4's all decked out. Help me outttt