Gearbox and transmission is thesame for us.

Unless you want to go Firestorm, with a single motor and a differential( keep in mind that Firestorm had 1 large and 2 small motors)

Also, I think the Speed 900 motors can drive a middle. If you use 4 of m. Each do easely 320W on 24V. If 259 in heavy config could drive on 4 simular motors....