Since these wheels are made-to-order, unless you're buying a used set...I don't see how you can say that FWD & RWD versions are different. I've seen both faces used on RWD cars, so who says you can't use both faces on a FWD car?
Also, since you seem to want 18s & nothing larger, I'd at least get a larger width...such as 18x8.5 or 18x9 to help you handle that power better.