The supercharger is useless off road, unless you are in the sand or mud..
Even on fire roads it is only good for making a dust cloud..
Most of the off roading i do is at 3 to 10 mph..
for a 2wd i woudl sudjest shackles for the rear, this would give you a little more wheel (down) travel, and might keep the tires on the ground.
just remember, as soon as you unload a tire, you are stuck. you may be able to reverse, or else you are pushing. I would also put in a rear locker, if you are going to try any serious off roading.. Huey in our club blew a hub on the last trip i did with him, his rear locker.. well saved his rear.. It allowed him to get up loose hills with only a cloud of dust, not a winch cable..