Thanks for the replies. I was thinking of using the Duplicolor roll on (or spray on) bedliner in the gallon can (brushing it on). I used Herculiner for the floor boards on my Mustang and it works well but it's too shiny. I'd like something tougher than regular auto paint since I'll be standing on it from time to time. I'd have it powder coated but phase 2 is adding a tire carrier so I'd have to grind off some of the powder coating (unless I did the smart thing and planned it all out before painting :ybrick

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Unless the Duplicolor bedliner is just poor quality, I don't think I'd have adhesion problems if I paint it over the epoxy during the 'window' before the epoxy cures, unless there's a chemical mismatch between the epoxy and the bedliner.
Any recommendations for a tough matte black paint? I've painted a lot on my car (lots of primer, engine bay, undercarriage, left the finish to the pros, but did finish paint some parts) and have the equipment to spray auto paint. How about tractor paint? (but not John Deere green, though I like Deeres). That stuff's tough and thick.