If you prep ot right, nothin wrong with regular rustoleum paint. Much less expensive than bed liner or undercoating and it will last. But you have to prep correctly.
what exactly would you suggest i do to prep it. so for the plan is to use engine degreaser and hand held wire brushes and scrub the piss out of it. then i will wheel it out into the drive way and wash it all down several times with dawn dish soap and water. then i was going to wipe it down really good with rubbing alcohol with white paper towels till it was spotless. then apply the por15 or rustoleum