www.rclipos.com
Anything from there that fits the required spec.
Only is being that the erevo has limited space in the battery trays:
5000mah 20-25c 3s lipo that will fit will work well.
There is a youtube video of someone testing the Kb45 with a prop (bench mounted) to simulate a load- it pulled 130amps:
http://www.youtube.com/watch?v=wqN4fsWxKrU
Vids of the Kb45 in trucks:
http://youtube.com/watch?v=zxeY_ZqO504
http://youtube.com/watch?v=Mlc3gsyTQFI