Triple,
A good powder coating outfit will know how to block everything off. Just make sure you discuss and ask a lot of questions when you bring your stuff in. The spoke holes are easily blocked off with silicone "plugs" and the bearing surfaces with high temp tape. If your PC guy does not have that stuff, maybe look somewhere else to get it done.
I think the red rim, black spokes and red hubs will look awesome. Kind of give it that cool pinwheel effect when in motion, the black spokes will become sort of invisible. I always wanted to that scheme on a pair of wheels.
Nth
Gersh