the 1000 has a high ROF but less torque
the 700 has good torque but less ROF

ROF what does it mean?
And Can batteries be too powerful for the motor?

ROF = rate of fire.

Battery voltage can be too powerful for a motor.
Battery capacity will never be too powerful for a motor.

Rate of fire is a function of mainly voltage, but is also strongly affected by capacity (in airsoft guns) due to differing internal resistances of different sized cells. As a result, if your battery *could* be too powerful for your gearbox. Strong and fast force pulling the piston backwards means you need an strong force pushing the piston forward to balance the system. In this case, you need a strong enough spring. Guarder SP110 should be okay for your 9.6v 2200mAh battery.