I would like to know how much paint would be needed to paint a 2 Ton Chevy 6100 with dump. I would like to paint the body and the exterior of the dump the same color. Will 1 gallon do the job or should I get another quart or gallon extra? Forest Green is the stock color. I currently have one gallon. The dump is now POR15 Black and it states you can paint over this product. Also, what color are the rims stock, green, black?