4wd's??? Off road??? Never.
I was up in Broome last week, about 80% of cars are 4wd (dirty , NOT squeaky clean), and most are more than capable. Jason if I was in your position I would go a Patrol or Hilux, and from some of the roads I've heard about get one with big tires & lots of clearance, especially since you've said that's where you want to go. AHG would help with the driving, but for practice just drive off Wanneroo Rd into the bush