One of the motors I had in mind for an hydraulic unit is [url:http://www.revolt.org.il/rv-160-mode...60-short/]this monster[/url].
The 81 KV is about perfect to be combined with 10S LiPo and a 5.8cc pump.

This delivers 200 bar peak with a 17L/min flow. A tad over your ballpark of 20mm/sec with 7 ton of force.