I am looking into getting an inexpensive kit too, so far ive decided itl need to be drive shaft, not belt due to my driving conditions.  Electric, not gas just cuz it seems easier, and more suitable.  After that I notice a 4wd kit that has a good center of weight proportion is ideal.  An hpi E10 or hpi sprint 2 drift stuck out to me.  Being a traxxas fan.  I dont know yet though, E10 d seems about right