I don't have any advice on the best paint but if you want to prep a bunch of small dings easily get one of these spot sanding pens. http://www.amazon.com/s/?ie=UTF8&key...l_8gfay764ml_e By just rotating the pen between your fingers you can precisely remove paint and rust in a very small area and works fast. For bigger areas just use a back and forth movement. Oh, and wear rubber/latex gloves and eye protection. These use very thin glass fibers which break off as you use the pen and can easily get stuck in fingers and eyes, not good.