Need a good vehicle for driving 1200 kms each way to the desert and back?

What type of car should we be looking at? We have a Toyota Rav4 but I feel it is too small for this type of drive especially if we hit a kangaroo. Would a sedan do the trip or should we be looking at a big 4WD? Keep in mind that we are in Australia so our options wont be the same as in the USA, we could choose a Toyota Landcruiser, Nissan Patrol, Mitsubishi Pajero and I'm not sure what else. But no Dodges or anything because they dont sell them here.