[pi_guy578]

>>How do I determine the required torque rating of the motor?
Attach a foot long pole attach it to the end of the motor shaft. attach the other end of the pole to a pull scale. Now run the motor until it stalls, record the weight. That's how much torque the motor has, measured in foot pounds

>>Any external control electronics necessary?
If its not necassary. You can just use a switch battery and 2 limit shitches to turn off the power when it reaches its specified position.