I have the underside of the box done with Epoxy primer and then sprayed gloss black rustoleum over that and then I'm going cavity wax it next year. I'm running out of time before winter and I want to work on the frame with the box off next spring so I'm storing it outside tarped over the winter. My Carquest guy turned me on to a paint. it's Dynacoat OPTICRYL C900 TOPCOAT. It's black and you can use a flattening agent to achieve the amount of gloss you want, or lack of and then a hardener. No clear coat. Thinking about going with that for the body of the truck. 350.00 a gallon with everything.