I've painted a few bike frames in my time using the rattlecan method. They all turned out like crap.

Out of all of them, though, the only one that ever worked somewhat well was Krylon Appliance Enamel, which is good if you like white or various shades of beige. Granted, I only sought solutions through my local Home Despot / Lowe's. The other expensive automotive stuff will probably work better.

My best advice is that whatever you do, if you do it yourself, is to take your time. Don't rush and listen to the waiting times on the back of the can. You might save a day or two but the crappy paintjob that'll result will bother you for a year, or however long you go without a repaint.