I am not doubting your experience Dave, but if I were to build it like you and Spareparts2 are talking about, I would have to buy 1 or 2 more cylinders with more stroke to be able to achieve enough travel to make the bed hit the ground. Or re-engineer my current setup to maximize the stroke I have now.
Maybe a telescoping cylinder isnt the best answer, but a dual action cylinder in my opinion is. Just for reference, this link is what I am going to be trying to mimic.
http://schwartzbodyco.com/videos/rollerframe-2.wmv