They are actually 18x9.5 wheels. I have 265/35/18's on the front...a little small. I had 275/35/18's on the back and they fit perfectly....both tires were Yokahama's.
I have since went up to a 295/35/18 BFG DR's to handle the power the blower added. It's a little taller than the stock diameter, but man do they fill the wheel well and look FAT.
If you are looking at tires just for the street and aren't making crazy power, then I would say go with 275/35/18's all around....that way you can rotate them. The difference from a 265 to a 275 is not even noticable.
Here's a pic of the 295/35/18 BFG on the wheel. Also one of the wheels in chrome on the car....