Here's a list of LT and the all position tires I've seen on this and other trailering websites although mostly boaters and other type forums. For some reason many RV trailer folks seem to think they have to use a ST tire.
The commercial grade Maxxis U-168 LT in 14" sizes..
Kumho 857 all position tire in 14"....
Michelin Agilis AS LT commercial application....
All the tires above are rated from 55 psi to 75 psi and may have a different rim width/pressure requirement than your wheels can support.
Check them out.