In case the hobby shop doesn't want to mount something, I have a manual tire mounter in my shop. I can mount any size tire that you want, as long as we can get it on there. It is great for big tires since the side walls flex easy. I also have the motorcycle attachment. I don't have a way to balance tires, yet. I have been looking at a static balancer, but it is a little ways down on my "tools to buy" list.
Gearhead-So what do you need to do to the YJ to get it going? I have owned a YJ for over 14 years now (that's 2 years more then R.J. has been alive) so I may be able to help.