Col is right, a brushless system will fit in anything - uhmm, ok no he's wrong. The mamba max wont fit in a Tamiya 501X - the MTroniks system wont fit in a HB D4 - etc etc..
The Mamba is a tight fit in the HB car but it will fit - you can file the chassis slightly to get an easier install. Should go in the lazer no problem I think.
The BJ4we might also be worth a look since it's one of the best supported shaft cars out there.