BEST PAINT NEED help
The word "best" is relative. About the most fuel proof paint you're going to get is 2-part automotive urethane. It's hazardous to use and expensive. I wouldn't hesitate to use it, but please be sure to follow the manufacturer's directions for protecting yourself.
I haven't had good success with the polyurethane paints sold through the hobby industry. I've had them come off with repeated contact with raw fuel as well as chip off the primer.
What does work well is good old fashioned dope.
Some guys are using Rustoleum, but I've never tried it so can't comment.