Wow...a Fajero! Mike, maybe some shocks with adjustable remote reservoirs to help dissipate the heat? You may also need airbags if it's sagging in the bum loaded up? I remember my Pajero over corrugations the dash would bounce around like crazy. I found you'd need to pick up the speed so it would kind of skip across the peaks. Ultimate suspension as mentioned previously would be a good choice to see.