Originally Posted by MichaelW
Off road touring bikes are a little different to sport MTBs. You need more stability, durability, touring brazeons.
Purpose built off-road tourers are available.
See
Thorn
Bruce Gordon
Gunnar
Sakkit do a "Great Divide touring MTB.
The Brooks Conquest saddle is an excellent idea. You get Brooks comfort, a little suspension to even out the bumps but no complex mechanism to wear out. The weight is similar to lightweight saddle + sus post.
Of the four you listed, I'd probably only go with the Gunnar for the Divide Trail. The Gordon and the Sakkit would be good bikes for touring but a front shock really helps with control off-road. The Thorn looks good but finding parts for a Rolhloff hub in the middle of Wyoming or deep in southern New Mexico would be next to impossible. And, even though I don't like trailers that much, a trailer is easier to use off-road than bags.