Picked up the wheels from the powder coater today. They did a great job of blasting them. I'm not sure what media they used, but they're very clean and not too rough.
The guy that did the blasting said that when they finish the raw surface with clear, it looks amazing. He said a lot of hot-rodders have manifolds, etc., done that way and it looks really cool. I took his word for it and decided to let him blast the whole wheel, tape up the rims and edges of the spokes, powder coat the wheel black and then have the whole thing cleared.
They gave me this weird heat tape to work with:
At first, I tried doing it in small pieces, but the tape isn't very flexible when making a curve.
So I taped up large areas and used a razor blade to trim it. Aah...much better!