Potentiometric Joysticks

Otto Engineering or Mason Electric. Both manufacture mil and commercial switches that should meet your requirements. They do custom work as well.

I'd forget doing things analog...digital control is much easier. Each motor would need an encoder. A simple microcontroller could have a small feedback loop so the shovel would stay in place if you let go of the joystick. An H-Bridge would provide directional and speed control for each motor. Good luck!

Thank you for your help,i think i will check into this.My big problem is that i do not understand electronics,i have been a millwright for forty years and have no problem with mechanical.I will try to find an electronics supply in Kansas City that will work with me,again thank you for your help,Floyd.