Hey Shark Boy - I am only new to this (joined today) but wanted to encourage you to travel with your family. I have done 2 trips with mine.
firstly from NSW to Cooktown (far nth QLD) totalling 7,500kms, then down through the outback on the way home.
The second was fantastic, from NSW to Broken Hill, Port Augusta Sa, up to Coober Pedy, then Ayres Rock, Kings Canyon, Alice, Tennant Creek, then to Mt Isa, Longreach, Charlieville, then down and out to Brisbane - totalling 11,000kms. It was unreal, so if you want any info on any of these places, drop me a line.
I definately recommend to take as much time as you can, unfortunately, we could only take off 5 weeks. Only just a taste. But, we will go again and are planning a trip to Darwin as we speak.
Have fun - drive carefully.