Well I know (or maybe, I just think I know) that the US has a lot more stringent laws on what sort of paint you're allowed to use, over here in Oz you can use acrylic laquer, catalyzed enamel (enamel with a hardener) and of course, 2 pack. (full of nasty cancer causing "carcinogens")
For bike stuff, acrylic laquer is probably the most "user friendly", and although not recommended, you can spray the stuff all day and it won't kill you. (but you may get stoned inhaling thinner vapour, fall down and smash your skull into small pieces, so it's a good idea to use it in a well ventilated area ) It goes on easy, needs only basic equipment to spray it, (a cheap "HVLP" gun and a two horse compressor, and a good filter/regulator assembly will work fine) and the results are excellent. Up until 10 or 15 years ago, all cars and bikes were painted with the stuff.
There's nothing wrong with "rattle cans" though, I did this tank with them!