Is it not acceptable to have part of the robot extend above where the object is, as in the yacht lift? If that's okay, it gives you more options, I think. I'm thinking four pulleys, 8" diameter, each on one corner of the crane, with aircraft cable or even just strong rope (200lbs/4 posts = only 50lbs per post and pulley).
How much is speed (how fast the robot lifts) an issue? Maybe you could work something out by connecting a motor to a hydraulic jack?
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I think it's rated for two tons, which might seem overkill, but could be quite close to what you need once you lever it to get your 2' requirement. $15 and for sale here:**broken link removed**