you can't powdercoat yourself unless you get the right equipment. i believe what they do is this:

a) sandblast wheels to get old finish off and clean surface
b) paint
c) bake in an oven at a very high temperature

the end result is a painted surface that isn't as delicate as typical car paint.

you could just take your wheels to a body shop and have them painted but you run the risk of chipping/scratching them a lot easier.

oh yea... and they DO sell kits for powdercoating... a friend of mine's uncle has one.

gug