Money is the big question. Electronics and vibration/outside/wood do not mix.
If it were me I would go hydraulic for everything.
-I would drive the feed with a hydraulic motor and limit switches.
-I would drive the swing with hydraulic cylinder and limit switches.
- I would drive the horizontal sizing with a hydraulic motor and some kind of screw with a fine pitch. I would put an encoder on the screw and shut the valve off when it got to the number I wanted (or just before to acount for overshoot).
Run the hydraulic pump from the motor or some other power source.
I would use a small PLC to drive the thing using whatever power I have available (120V) or 24V DC (2 car batteries together). I would use a digital display (serial best or some kind of BCD number switch) to tell the PLC what size I want the boards to be.
To do it this way and using Ebay for as much as possible it will cost you a few grand. The money is in the motors and pump.