Nice 4Runner Mike. I had a 3rd Gen as well, this is how I had the rear of it organized and it worked very nicely for me. Those are Zarges cases lashed to the Hi-Lift, which was held down with wing nuts and mounts from Sonoran Steel.
I usually only traveled with one other person so there was plenty of room, but if you have kids I think that a roof rack with an awning and space to lash dry bags with light stuff like a tent, sleeping bags, and clothes would be the way to go.