If you get 15" wheels, I say either 195/60 rated tires or 205/55 rated tires.
If 16" wheels, get either 205/45 rated or 205/50 rated tires. check out
www.g20.net/rr_main.html both the p10's their have 16" wheels.
Stock P11 wheels look pretty good too. The new 16" wheels that come on the sport package are very expensive so you probably want to get the older 15" wheels.
I'd get at least 16" wheels if possible, should be a fine ride with the right size tire, potholes shouldn't be a real big problem.
Here's what the stock p11 15" wheels look like...not a good pic...