nbucska is right in terms of the need to define the power (torque and speed) of the system. It is true that with the right reduction any motor will do the job (provide torque). How fast you want to perform the work will define the power requirement of the motor (HP). I will add that an engine starter motor is a good choice for a small sized, high torque, 12VDC motor, but it will not be rated for continuous duty. I am guessing here, but I would be surprised if such a motor was rated for greater than 15 minutes duty (per hour).
Please provide more info as I am sure that someone in this forum can help.