Why not remove some leaves, and put some air bags in place? Smooth ride, but still able to pump up, and carry big loads? You can get less expensive kits with no compressor at FLAPS for $350 or so, at least here. They come with brackets and stuff, a little adapting and away you go! You just air up at the shop, or gas station. This is my plan for my 1/2 ton panel truck, so I can tow, stay level, and still have a cushy ride the rest of the time.
I found, with a yard of gravel or sand in the back of my 1-Ton, it rode smooth like a Caddy. It was a bit slower though......
