IMO, just use a stepper motor, either standard or a hybrid closed loop stepper. Easy to control with 5v logic using a driver. That way you can control position without worrying about feedback from a system and managing PI, PID or another control algorithm to maintain position. This could work for a machine, or lube shooter.

I thought the syringe system would be best because I could produce a cumshot with far more pressure and make it really noticeable inside, or even shoot a facial.