3/4" high grade plywood, 2x2's and a whole lot more time than I anticipated. I coated the whole thing in Herculiner. The D-Rings are attached with 1/4-20 T-Nuts and black coated hardware (hard to find!). They're laid out to accommodate our 7G water and three Plano HD storage containers.
The slide is made from some 2" aluminum angle and some 1" aluminum angle along with a 220lb full extension slide from our local Rockler Woodworking and Hardware. Fastened together with as many rivets as the slides had holes. It's attached to the Plywood through both it and the 2X2 with 1/4-20 T-Nuts. Fridge is the Indel-B 50qt from Equipt and the ARB tie down kit.
The table slide is aluminum plywood end cap channels from Home Depot, works well. Table was coated with Rustoleum Countertop Coating. Cool paint, makes a very smooth and resistant finish. Legs are just dowels with the appropriate table hardware from Home Depot, screw on in short time.
The entire try/slide is fastened to the truck with 1/4" turn buckles. I would have went larger on these but no one makes a larger diameter at the necessary length. I sat my 105lb girlfriend on the slide when it was full out and it didn't budge at all so I think we're good. Whole thing comes out in less than 5 minutes. Works VERY well and I am amazed at how efficient it is camping. We made it so our chairs and stove fit underneath. Stop, pull the fridge and table and slap the chairs down and have lunch. Excellent. Hope this helps someone with ideas.