Re: How much paint do I need to buy
One primer and 2-3 finish cans should be plenty. They make ceramic paints that are fuel resistant. Some of that in clear around your gas tank area over your color coats will help save the paint when you inevitably splash. Gas isn't friendly to rattle can spray paint. Several thin coats, follow the directions on the can for recoat times, and let it fully cure before you start reattaching parts.