Ah - in which case Tekin all the way. Definately worth getting the slipperential - Randy Pike actually advised me to get one, and said they had been using it. He referred to it as a 'great tuning tool' or something similar.
You can also get the battery boxes from RC-M, and I think it best to get one of the custom sized versions - so it fits your packs like a glove.
__________________
|