A color name isn't really enough to go on. I recommend reading up on d-I-y websites for auto refinishing to learn the basics of the work required. A quart of anything is enough to paint a Busa complete, but of course we are talking about a quart of primer (maybe), sealer, base, candy, and clear plus the necessary components to add to those products. By necessary components I mean activators, reducers, etc.
If you haven't chosen the paint product you may want to check out House of Color. Keep in mind that a candy color is much more difficult than a metallic base/clear, which is a little more difficult than a standard base/clear. I don't recommend a candy for your first attempt. If you want to go with a more standard paint I recommend visiting your local auto paint store and getting their recommendation for their budget line of refinishing products. They work well and cost less but aren't as good for repair work on cars. For an overall or color change this doesn't matter.