You can also get enamel and flam finishes done by framebuilders - Vaz finishess in Essex are particularly good.
Flams paint the frame silver, then apply a transparent (coloured coat) and then layers of lacquer. You get a really deep metallic colour - it's the same technique as done really special custom cars (i.e. not hopped up Saxos.)
I did it on a Pine Mountain, and it looks really, really special.
Whatever you do, avoid car paint and car sprayers. Car paint chips too easily and car sprayers are very good at large flat expanses but find it hard to do tubing - usually because their guns are too big.