If they're Jap rims, I'd personally go professional powdercoater.
I sprayed my 34 GTT ones with a $20 can of paint from Supercheap Auto, but with my SSR's, Martin from Diamond Powder Coaters in Welshpool sandblasted, primed and topcoated a set of 17 x 8.5 rims for 55 per rim. Best price I could find, and the work was top quality.