dustboy
Explorer
This idea is exactly what a company in Idaho Falls Idaho was doing for awhile. When the shell was lifted at each corner, two platform beds were extended to each side. I know of a guy in town that has one, I will try to get some pictures and information from him.
I would love to see how that was done. Do you know the name of the company?
For the weight of the lift, you could have some gas lift struts to counterbalance the load.