@RA: If you paint it, use spray paint, particularly automotive paint. It'll stick very well and won't chip. You'll need to gloss it after, too. Professional painters who do custom video game console and accessory paint jobs use automotive paint.
If doing by hand, get a PVC primer first to make sure the paint sticks.
awesome you sound like you know what er talking about ^.^ have you or do you plan on ever doing a tamagotchi like this? if so can you post pics on a how to for us please <3