
Notice the two coil over shock units. They are to the inside of the wheels, and stick up. They would stick above the floor. They might be replaceable with air bags. Another detail is the cross beam. It would work partially as a stabilizer bar.
Because of the coil over shock units intruding into my limited floor space, I think I'd stay with using a torsion axle for now. It is a complete bolt in unit with simple mounting. Also it is a standard off the shelf part so replacements should be easily found.