About 12 years ago took the wife and kids on similar trip. Three weeks all up.
Sydney to Port Augusta, via Mildura, the straight up to Cooper Peddy, the to Ayers Rock, Kings Canyon, Boggy Hole, Palm Valley, Hermansburg, Alice Springs, followed the old Gahn Railway south, then oodnadatta track down to William Creek, then on to Leigh Creek, then across the norther part of Flinders Ranges onto Broken Hill, Dubbo and home to Sydney. From memory about 7000 Kms. A great adventurous holiday. Did a lot of free camping except for main stops.
Kings Canyon was great, Boggy Hole was great, Palm Valley was great. Could write forever, but I will not bore you.
Brings back memories.