Powder coating is, by far, the most durable. You can literally strike a powder coated object with a hammer and dent the unit without chipping the paint. As durable as our calipers are I was always under the impression the calipers were already powder coated? Forgive me but you make reference to both "Paint, and Powder Coating" and there is a huge difference between the two. There are companies that will powder coat anything, check out your local phone book and good luck.