I have not used any of the "professional" spray on bed liners, because they're way expensive! What I did, instead, was get some Hammerite.. black, hammered finish.
It took 5 cans to cover the bottom of the bed (laid it on THICK), and 3 to do the sides and rails. This stuff is hard as a rock.. I threw a Dana 44 front end in the back the other night and hauled it around.. not a scratch in the paint. It's good stuff.. and it covered up the rust, too.
Can't beat it, for a spray paint anyway..
