Here's what I came up with today, not perfect but I need to get this done! Don't look at my lousy welding, if this thing were visible I would have spent more time making it prettier.
Paint tomorrow and find some hardware. Should I use stainless only?
The only problem I realized is that since I have a 2wd I will have to drive the van up on blocks to get a floor jack with the batteries and tray under the van.
This will be an absolute PIA if I ever have trouble with it on the road!