You have to find a shop that does powder coating. Most larger cities have at least one shop that does it locally. However, they might make you sign a waiver on the wheels as the high cure temps of powdercoating can possibly soften the wheels.
Rick
Owner of 00 #1611 Silver (Totalled) 98.5 T-Red SVT #6180
Buckshot77@msn.com
Misc 3L parts for sale