Gotcha. What I mean was the tire will wiggle a little bit when offroading. I'm sure I could figure out a way to stop it but I don't see it as a problem.It's hard to stabilize something like that because its so heavy, not sure what is rattling, but as funny as it sounds, I have found bungee cords to be great at holding things together. If you bungeed the tires together with some heavy duty bungees it might help. Unless its the rack that is moving/rattling.
As far a Jack's go I have a small bottle jack from SafeJack that has some extensions. It comes in a bag that I move pretty easy. It has all I have ever needed with my truck or my Jeep. I just limp it to a good safe flat ground and it works. Not seen a reason to buy a big jack yet.