hey,
I've found this conversion kit for 1:5 cars:
http://www.riverhobby.com/1-5electric.asp
the motor is a feigao, the equivalent to the kb45 xl, but is supposed to be better quality then the kb. 6s (ezrun) seems small, but for 2wd it should be ok, I think.
they also have a conversion kit for the himoto truggy. looks good.
florian