Yikes...I would not even want that kind of load on the tailgate.Here is another type that I have been considering. Costs a little more but may be a little stronger. I have seen a couple of these used for $1800. I haven't seen either one of these types up close.
http://www.rampagelift.com/index.html
Ah...looking at it again, I see what you are talking about.There's actually little or no weight on the tailgate...