'50 3100 pickup. I will be painting entire exterior. Backsides of panels will not be painted with exterior color. I plan on doing a BC/CC job. Will be spraying epoxy primer, high build 2k primer, bc, cc. (Plan on using middle of road paint and products, but will tend to move up on quality rather than down.) What is a safe quanity of the various products to be sure that I have enough, but not a lot left over. Thanks in advance.