If you have a very flexy suspension or a large lift you will need the 60", otherwise a 48" will do. I have a 48" and it works fine on mine. There are several mounts that work. Hi-Lift makes a mount called 4Xrack that can be mounted on any flat surface. On my CJ-7 I mounted mine on the rear wheel wells behind the back seat, but that limits you on how much you can put in the already small space.