Karl Townsend wrote:
For your application, I'd consider air cylinders. Exhaust restrictors to
control speed, stops on the rods for location, solenoid valves for the
electric interface. Very low cost,especially if you look at surplus items.
Good for many 1000s of cysles without maintenance

Given you want to position your load, not just push it into a stop, I'd
avoid air. Air is compressible, so you're essentially pushing your load
with a spring. When your feedback system says "done", you still have a
cylinder full of pressure air, which will keep it moving.
As others have said, some kind of electric motor system (screws, wires &
pulleys, etc.) looks good.