My suggestion is to ditch the hydraulics all together! Watch this video for the skidsteer version,
http://www.youtube.com/watch?v=VXkdQ...SHzYYNJCBCD70g they have a chain that continuously rotates, sprocket at top and bottom of the stroke, it has a finger that catches the weight, lifts it to the top of stroke, and drop's it! They rotate the chain with a hydraulic motor, a major pain in this scale! Electric motor and gear reduction would be cheaper to drive it with. That's my 2 cents worth.
Cheer's, Neil.