What size Twist wheels fit best?

[3point2]

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.