Options for camera gimball control using Arduino

You need at least two output pins to control each stepper. You only need 1 for a servo. Do you know if you have output pins to spare? If you want to be able to recover automatically from a power failure or reset you will probably need one more pin for the home sensor/switch.

The second video seemed to be showing 3-axis stabilization. That would require a YAW output from the controller.