For my 2002 S2K:

Just received delivery from the Tire Rack on my 18" SSR GT 3's with Bridgestone PP SO3's 225x40 (F) & 255x35

 

Jim knows his stuff. Trust him.

 

Jim from The Tire Rack IS a professional.

 

The wheels you selected are front: 8" wide (+49 mm offset), rear: 9.5" wide (+55 mm offset). The 2002 OEM wheels are front: 6.5" wide (+55 mm offset), rear: 7.5" wide (+65 mm offset). When you do the calculations the GT3's will stick out more, front: about 1", rear 1.7".

If you go out to your car and measure that off of the OEM wheels you'll be very close to the fender and tires probably won't tuck in over bumps. When your lowered better chance to rub. Putting some camber will help "tucking" in the tires, but will cause more wear and change the handling a little (if you are doing autocross or roadcourses for the better).

Jim knows what he is talking about with S2000 specific wheel and tire stuff.