Being not aware of your requirements but I think if I had this problem I would be looking into renting a motor home in Australia... Shipping transportation has got to be hugh for doing this... Kinda hard to drive to Australia unlike Mexico and South America... There is also all the headaches of license requirements for both the truck and 5th wheel trailer I would think...
Who knows about all of the being safe rules... i would probably loose my whole caravan the first night on the road haha... Being a rig setup from the states would for sure stand out in the crowd down under...
Of course we all have our dreams on things to do... I've been drooling for years over their off-road vehicles... They for sure have got all of that down pat... All too expensive for my pay grade...
Roy Ken