Yes a 18 x 8.5 will be fine....

Are you kidding me. A 18x8.5 would fit. Remind yourself what stock (2000-2001) is first before you persued someone to not by a rim.

I would work in a 255/18 tire.

People are ridiculously way to quick to say things will not work when it comes to rims. I have had 16's,18's and 20's on.

Just pay attention to the offset, and overall diameter of the tire you like.