Start with a VXL system. CRP on the traxxas forum has been selling them off the 4x4 for a great price for a while now. Then you can upgrade the ESC later and still have a good motor in the truck. However on of
these is a must. I am looking for a liable replacement for the tranny case here soon as well, the plastic holds up decent but somehow my wife still manages to get sand in there. I will be going aluminum soon.