Tamiya do make a CC01 unimog kit and a CR01 unimog kit they might be worth looking into
im 99% sure the CC01 had differentials, it has a solid axle at the rear and interdependent suspension up front
and im not to sure but ive got a sneaking suspicion that the CR01 might too but its got solid axles front and rear... either way tamiya does have parts for spools or differentials
just keep in mind, the tamiya kits are considerably smaller and not as capable as a scx10
http://www.rcmart.com/tamiya-58609-c...cPath=420_1167
http://www.rcmart.com/tamiya-cr01-me...cPath=420_1167