Well, depends alot on your budget, intended operating voltage& truck weight.
But.... I have heard of alot of people using dual MambaMax motors and escs- I would suggest either 4600kv or 5700kv depending on how fast you want to go. Or you can try a couple of Lehner basic 4200kv with appropriate escs- the motors can handle up to 10 sub-c cells which is 12v. Take a look at the Candyman's dual BL Juggernaut2:-
http://homepage.ntlworld.com/ryan.coombes/bljugg2.htm
Should give you some good ideas. But remember, the heavier the truck, the more it will strain smaller motors & the more you will need to gear down.