Yup , powder coating is the way to go , I use Embee in Sta.Anna , Ca. right off the 55 fwy & Edinger Rd. , your wheels will stay bright forever and the brake dust washes right off .
Lots of colors available too .
Be sure to ask soeone else before you use a new powder coater though - I got some wheels done up here in the SFV and they sucked - fish eyes all over etc. , wasn't any cheaper either .
All the show car guys use Embee and they cost no more than the rest .
They do this neato coating for the exhaust manifolds too , looks grey (ish) like metal .