I would stay away from Herculiner and other roll on applications. I have found a DIY spray on bed liner that is supposed to be comparable with Rhinoliner and Line-x.
I found a product by the name of Al's Liner
alsliner.com that has turned out to be a great product
quite a few guys on cumminsforum.com have used Al's liner with great success!
here is a link to my thread, a lot of reading but there are quite a few photos a couple pages in.
Al's Liner DIY Spray In BEDLINER kit.... - Dodge Cummins Diesel Forum
Eventually I will be doing the side of my 2006 ram (rocker panels) but for now here are a couple photos of my toolbox in the bed of the truck along with the boxes I put on the sides of my gooseneck, and a stand for a strobe light for plowing.
**Note the texture of the material can be controlled from the gun** I used a thicker clump since the boxes will be used and abused