@Warren
Nice skeleton, perhaps you could fill in a couple of organs. Heart, one lung, a kidney and that all important male only prostate.
I have a bit of experience flying around Asia, the Shakey Isles, and the Great South land. Business Class.
At this stage I presumptuously presume that for Australia you are looking at the usual draw cards. Sydney, Barrier Reef, and Great Ocean Road. In which case September is start of spring and usually a very pleasant time on the east coast, while in NZ is still cool to cold, particularly South Island. Consider starting on the east coast and scheduled NZ at the end.
Up front, what are you hoping to experience? Surfing, scuba on the reef, whale watching, bungy jumping? Are you the type of traveller who needs to do this on the cheap? Are you young, romantic and athletic or senior and passive sedentary?
Kind Regards
Ron