I am by no means good at painting bikes but I like Montana Gold range for painting. Thin layers with 1 hour in between through the day, leave to cure 24h, wet sand, repeat process day after until it has build up a nice durable coat and is smooth. People swear by etch primers so that's probably a good bet. I'm more interested in it lasting than it looking good, as I only paint the frames for rust protection.
@Canuckbiker had good results with the Montana, perhaps he'd chip in. I initially recommended him Montana after he had reservations about Spray.bike. It shares some of the same traits but I find Montana more durable and far cheaper.