Wow - so many brilliant replies from all you lovely people!I may PM some of you for extra info but am already compiling a list of things to take or ask travel agent about.
Struggling2do1 - Our trip is exactly 1 year after yours so will lookout for your post-trip report! We are going with Austravel. It starts in Perth then goes to Alice Springs, Uluru (doing the sunrise trip),Port Douglas, Cairns, Melbourne and Sydney. Did the bridge climb in Sydney and trip to Rottnest island off Perth on 1st visit. Fancy seeing the penguins on Phillip Island near Melbourne after seeing it on Martin Clunes' recent programme on Australian islands. Just seen that Magrithea has recommended that.
In NZ it includes Aukland, Rotorua, Wellington, Christchurch, Lake Tekapo & Fox Glacier.
Izabella mentioned holiday insurance which I have looking into as would normally book it at same time as the trip. Several companies that I have tried have said that they can't arrange it more than a year in advance. As we are only a few days away from that time frame, I have accepted that it will get sorted then, and hope that nothing happens to either of us in the coming week!
ClaraB - good luck with persuading your DH to retire.
Kim - disposable undies are a brill idea which I had thought of for me. Not sure that DH would be keen to use them though.
Pleas keep your comments coming, they are really appreciated.