X2. Chassis paint is made more for the grime and crap you encounter on the road. It protects the metal and prevents future rust better then anything else you will find just because that is what it was designed to do from the start. It will also stay cleaner and hold less dirt since chassis paint is smooth. Bedliner is great, but it holds the dirt in the texture quite a bit more.
Complete rebuild axle/engine/everything swap in progress: Building stock width 44's with 302 from 01 Explorer. Motor has GT40p heads, Cobra Intake, and truck cam. Running A9L EEC IV stand alone engine from late 80's-90's Mustang GT. Big Bearing NP435 married to NP205.