Post some ideas, I have a tonneau cover and stuffs sliding around in the bed. So i'm thinking of building a small storage container, out of some wood and carpet. Nothing as hard core as these guys, but you get the idea. It will keep my tools from sliding around.
I'm a carpenter and I have had all sorts of truck bed liners. In my experience carpet just gets wet and dirty and is a pain in the ass. The best setup that I have found for keeping tools from sliding around is a simple rubber bed mat. It is resilient, easy to clean, and does a surprising job of holding everything in place.
I ended up placing a large HD storage tote in the bed, it fits snugly and keeps everything inside out of elements.