Go to Monstaliners website. They have a paint called chassis saver, it is designed to be painted over rusty areas. Scrape/wirebrush the loose stuff off, clean and dry, and paint over top. Then you can go over top of that with a bed liner. I used Monstaliners bed liner and I think it is the best bedliner you can buy. It is an epoxy paint, and the texture is acquired through spraying or their custom rollers they sell with their kits. All other DIY bed liners I have come across use ground up rubber or some other type of flake for the texture and is easily worn off. I went over the bed rails when I did mine and have yet to chip or scratch it, the stuff is very durable and looks good.