Funny this question should come up, I'm in the middle of renovating my mc21sp and spent a fair amount of time looking at the best option to finish the magtek wheels. Just finished them today. This is what i decided after alot of investigation. As stephenrc45 says powder coat is not the way to go. Paint is the way and this is the process
1. Orbital Sander to clean off as much of the old finish as possible.
NOTE: DO NOT USE ANY CHEMICALS TO STRIP THEM.
2.Hard work but worth it, by hand to take of the rest.
3.Once you have them looking something like back to bare use glass etch to a finish.
4.Four coats of base primer flatten out between each this will highlight any cracks.
5.Two topcoat color of choice.
6.Two coats lacquer.
Finish is awesome
Hope this is of help