On one hand, having one bumper painted and the other chrome seems odd, even though that's how the factory did it. On the other, with the rear painted, it may throw the proportions off when viewed from the back. I think the new Challenger has a fat butt, at least from the pictures of the rear and I think it's because there is so much orange down low. It needs a more horizontal statement, IMO.
My suggestion is that if you're going to have the bumper re-chromed, get a rattle can and paint it. Stick it up there and see how it looks. If you don't like it you can always chrome it as before. As for the Foose....getting rid of the "warts" and getting things tight is always COOL!