Get etrack for the floor as it gives you lots of flexibility for tie down points. They also make etrack for mounting on walls, vertical etrack as opposed to the horizontal for the floor. I have vertical etrack going up the walls in the front. To that is attached some etrack compatible brackets, and then bars are hooked into the brackets, and run across the front of the trailer. Resting on these bars are plywood. So, this gives me shelves that are adjustable up and down, and removable. I put another bar closer to the floor, to hold in a toolchest, stands, etc. I put lubes and stuff in milkcrates and bungeed the crates to the shelves.