Duplicolor is definatly the way to go. I use it for priming rust spots on the folks cars. I also use it on my bike. I use Sikkens automotive paint for color but that is just because I work in a place where I have access to all the painting crap I need, but yeah any duplicolor is good rattlecan material.
Autozone, O Reilley's, I believe Advance Auto Parts has it. No more Checker or Kragen lol, big O bought them out.