The more capable your vehicle gets the further and"harder" you will "offroad". In your endeavors you will always be chasing the weakest link, weather it be you or in the makeup of the vehicle. You will ultimately get stuck somewhere, hopefully you or others will not be hurt. The more remote and alone you are adds to the excitement, but also adds to the danger.
How would you repair such a vehicle in the remote areas of Maine or Montana, Idaho, if only on a simple logging road, with no one around for miles and miles?
It is best to participate in this type of event, and or racing in an organized function with other participants and safety personnel on hand.
Simple is better.
IMHO the H 1 Hummer is too complicated and special for your intent.
JIM