IIRC a current is passed through the frame which attracks the powder onto it (so that's why it probably wouldn't work with carbon frames not withstanding then having to bake the frame too) then its baked to cure the powder.
Anyway, I digress.
I have a mate who is a painter. He hasn't done any cycle frames, but he paints scooters (Lambretta/Vespa) and does motorcycle race paints and air brushing. Don't know whether he would be interested in doing it but I can ask him if you like, oh and he works in Barnsley which is pretty close to Wakey.