Which Lipo Battery To Use With Mamba Max Esc?

[truckbuilder06]

I Have A E-revo Project Which Has The Tekno Brushless Conversion Kit,mamba Max Esc, Feigao 9xl Motor,15t Clutch Bell, 38t Spur Gear, And Stock Tranny 2nd Gear Locked, Cvd's All Around, Front,back, And Centers, Manual Brakes,and A Ubec. My Question Is Which Lipo Should I Buy? I'm Mainly Going To Bash With This Revo On Loose To Hard Surfaces. Looking For Long Run Times With Some Nice Top End Around 40mph Max. Just Don't Want To Fry Anything. I'm Looking At Max Amps Lipos, But Which One To Get? 6000, 8000, Or Something Smaller, Any Recommendations Would Be Very Helpful.