Go with the powdercoat! You should be able to get very close to the color you need if not exact and powdercoat is the only thing that is going to hold up to the road on a frame. I saw a bike at a show not long ago. The guy that painted it was so proud and it was a sweet paint job, but he painted the frame the same as the bike and didn't powdercoat it. When he bolted everything back on, he took out some chips that a quarter wouldn't cover. It looked like *&%#! Go powdercoat on the frame! Save yourself the "Geez, I wish I woulda..." routine. Unless it's just for show and you're going to trailer this thing everywhere, really consider how much work you're putting into it and do the math. POWDERCOAT!
FT