If you go here you can see the packs I am using
http://www.maxamps.com/index.html?lmd=38771.571875
I have the Lipoly 6000mah 3S2P 11.1V Pack for $119.99.
Rated at 60 Amp Constant Discharge
Rated at 72 Amp Burst for 10 seconds
I hope that battery pack has good enough discharge for what I need.