I've been looking around for a used set of Porsche 18" twist wheels and tires lately that I would like to put on my 03 S.  But there are a slew of different sizes I've been running into.  So now I'm sort of confused 
 
What is the most optimal size 18" twist wheels and tires I should be looking for?  I will be lowering the car with Eibach or H&R springs eventually.
- Front and rear wheel widths?
- Front and rear offsets?
- Front and rear tire sizes?
- What front and rear spacers needed (if necessary) to make the wheel/tire flush with the fender?
Thanks for the replies.