I think it would look sweet to get gunmetal rims on black. I would agree though that you should paint a CF hood. It wouldn't be enough of a contrast with the rest of your car, so you'd probably get a lot of "why is your hood a different color" if you hadn't painted it. If you got black racing seats with red accents, and maybe painted you brake calipers red, I think that would look real sweet. Though I did hear that painting the calipers is a bad idea, but I don't know anything about that...