How much paint to buy?

Well, I don't know if I personally will be painting the car or not. I know a guy who has been painting cars for a long time. You know, one of those cousin's boyfriend's roomate's best friends type things. So I am going to try and get him to paint it. But if he won't, then it will be me and a different friend who has a degree in autobody. But actually, now that I think about it, I may just wind up leaving the engine bay black. I was going to paint the bay the same blue as the car and do blue/chrome for the engine. But I think that a black bay with black/chrome would look better. And for all the haters, I know, chrome = But remember, I am building this car for show. And while chrome = it also = points.