Hi.
I have an older model herters one that I got from cabelas when they were clearing out old herters stock a few years ago. It is height adjutable with pins, and it works on my lund with reasonably high sides (not sure how high the sidea are on a livingston - but the lund is not a sneakboat like many here). Works pretty well when I use it. If you can weld, you could make one up just like it without too much effort. If you're interested, I can post pictures (I've posted them on the old DBHP board before).
Charlie