This entire project can be done without any welding. Main supports can be bolted to the frame, Secondary supports bolted the main beams and 1/4 plate bolted to everything. It takes planning to have holes predrilled before assembly of some parts. If you can find my truck pics you can do all that without welding. I would not use anything less then 1/4inch for the plate. 1/8 is to light. it will bend dropping heavy tools and parts. But you do need to use all galvanized nuts, bolts flat washers and lock washers. There is not welded aluminum on my truck. Send my a drawing of what you want it to look like and I can give you a cut list of material. I have a Dodge shortbed on site for truck specific sizes.
