We did 3 weeks to Uluru and Back in September in the Prado. I looked at a heap of setups and decided that to use the KISS principle.
So the basic set up was:
Small roof basket with rooftop bag. The rooftop held our 2 small 2 man dome tents, chairs, sleeping bags, mattresses, small table, 2 burner stove and recovery gear / tools. Maxtrax things were cable tied under the roof rack.
We also had an ARB awning on the passenger side of the roof, 3 metres long x 2 metres out and we slept on a tarp on the ground under this on a couple of nights.On the drivers side was a long handled shovel attached with Quick Fists.
Inside we had a 105 litre vinyl water tank on the floor behind the front seats, our kids are young so it didn't impede their leg room. Going where we were I probably over did the size but better safe than sorry. The brand I bought was Fleximake, I think, and they were very good to deal with, no afflliation.
In the rear we have a large single draw that we filled up with dry food and anything we wanted easy access to and a 40 litre Engel for cold / frozen stuff. Between the engel and the rear seat is a convenient spot that holds a 2 cubes of beer. We allowed a Coles insulated bag each for clothing (so 4) plus another for toiletries and those microfibre towel, 1 for cooking gear and utensils, and another for kids books and stuff. There is also a fold down bench inside the back door of the Prado that we used for food prep etc.
Finally the spare wheel had the Binbag / Dirty storage and this was used for rubbish / dirty tarps etc etc.
As we were doing fairly high k's when we were driving we were setting up camp about 3pm in the afternoon and leaving by about 8am or 9am the next morning. So were looking for shade trees, and found them most places we stayed and stopped for lunch.
From my point of view the best thing about our setup was the time to setup and pack up and ability to travel much faster than those towing . The worst thing was making sure everything stayed organised. If you don't stay organised then your whole system can fall apart fairly quickly.
Have a ball, sounds like a great trip.
Cheers Nomad.