Your only other option if you want to try anyways would be after they are powder coated to take the wheels to a paint store & see if you can get the color matched with a spray bomb & u could do your center caps that way.. but idk if i would trust that coz paint comes off to easy..

If anyone else out there interested in getting some stuff powder coated let me know.

Valve Covers
Charge Pipes
Springs
Wheels
Strut Bars
Diamond Plate
ANYTHING METAL