Looking for stepper motor control and an output.

I have this job of taking pictures of a single frame on film. So looking at using a stepper motor to advance the film one frame which should be a specific distance on each frame and constant. Then once the stepper motor stops trigger an output to make a switch that takes the picture. Then advance to next frame but may need to pause for a short period till image has been buffered out. trigger the output to take picture and advance to next frame. The picture software can be controlled off a USB foot pedal switch that I say is a simple device. Never cracked it open but guessing here on that it is a switch on the foot pedal.

Not looking at anything from scratch but a premade board with simply software to control a stepper motor and and output will be just fine. The picture software is always ready till foot pedal is pressed.

Thank you for your time and help.
Brian