DIY bedliner is popular with Jeep enthusiasts, of which I R 1. Guys do the entire tub (cab and cargo areas) using the various products that are out there.
My advice is, by the time you buy the product, do the prep cleaning, sanding, cleaning again, mask the truck and then do the work, you will wish you had spent the $500 or so to have Rhino or Linex do it.
A Jeep is a different animal, requiring a lot more disassembly before you can even start the prep, and DIY makes some sense. A truck bed, not so much.
2006 F250 Diesel
2011 Keystone Cougar 278RKSWE Fiver