That’s a good idea. When I designed my rig I was sure I wanted a floor for it. My plan was to place all the electric and electronic elements on it, especifically under the seat (power strip, USB hub, shakers amplifiers, different power supplies, cables, etc. What I did was to order a sheet of laminated plywood (1,9 cm thick) of the same size of the base of my rig. I screwed the wood to the profiles from underneath. I also added some sliders made of teflon to the wooden base.