My best friend is on his 2nd Hi-Lo, both of which I found on the net. His first was a 22 foot and now he has a 31 footer. Pulls it with his 2006 Dodge Ram with the 5.9 Cummins. Last 2 years he, his wife and Catahoula dog have gone up north for the summer. The truck averages 16+mpg over the entire trip.
He is very happy with it even though it is a 1994. The newer ones are built better and are worth considering even though the price might seem a little high.