On Tirerack's site, they have two different pictures showing the difference in the wheel face for the 8"-8.5" and the 9"-9.5". It looks like the 8"-8.5" will still be somewhat concave, as opposed to being completely flat, which could kill the look of this wheel. It's not as obvious as the wider wheel, of course, but still looks like it could be a good option. Hopefully the 17x8 +40 will turn out well.
8"-8.5"
9"-9.5"