We have now driven most of the east coast of Oz in a camper, and loved it. We also have a kombi that we are shipping over when we move this year.
Big things we have learnt:
Campsites in oz are nearly always far better than in the uk
Cleanliness and upkeep have on the whole been better than we are used to in uk
Dont bother with carrying a shower and toilet, its just an expensive store cupboard!
Booking sites in advance has only been an issue in school holidays, public holidays, and grand prix week in Melbourne!
Book the camper early has always got us a good deal.
Go the opposite way to everyone else for a good deal too! ie start in Cairns and finish in Melbourne, as you then save on the one way hire as you are bringing a previous rental back to base, it may even be worth finding a good deal, and ask about doing a van swap in sydney to save the company relocation fees.
Also, all the sites we went to had gas barbies, so armed with a $15 bar be mate, look at coles, you dont even have to have a cooker.
A few sites we remember:
Main beach touring site in Surfers is nice, across fro the beach, and a nice walk into surfers, maybe 1.5 miles
Lane cove in Sydney, National park site, 5 minute walk from the station, our first meeting with posums was there at the barbe
Kiama had a nice site, cant remember the name, just south of Sydney
A few places off the main road to see:
Hyams beach at Jervis bay, South of woolongong, unless you go know you'll drive by on the main road, lovely place with the most gorgeous beach.
Cape otway light house, down on the great ocean road - on the road in look out for koalas
We have booked with Mauri, Britz, and motorhome bookers, it really is a case of comparing prices to what suits.