I would use a Dodge Ram 1500. if its too much over 6', I guess I'd use a ratchet strap, too. I'd use an appliance dolly, too. one made to go up steps and curbs. I wouldn't trust my drunk friends with a tank, except for a few seconds at a time.
If I owned a lfs, I'd offer delivery and installation on large aquariums. heck, I'd offer on all aquariums. Why not maintenance, too? I'd probably make as much money on that as on the retail end. business would be great.