a wheel repairer once told me never to power coat wheels...
while it is very hard wearing it isnt suitable for wheels esp if you drive hard. when you get your brakes hot, heat is transfured to the wheel (try touching the centres after a thrash threw some corners with heavy braking!). due to the nature of power coat the heat softens the paint and brake dust then sticks to the powered coat surface.
for those who dont know, when something is powered coated, it is first heated in a large oven, its then covered with the desired coloured power then baked again, the power melts into a liquid coating the metal.
2pak is the way to go.