Ladies - I agree that it is a very long trip. My last long trip was to Greece in 2004. The first leg to Singapore was fine on a smaller more comfortable aircraft; then a changeover to a Jumbo 747 for the long haul from Singapore to Frankfurt; and then, BLISS, the rest of the journey from Frankfurt to Athens was on a new Airbus with a much alcohol and food as you wanted for free, that was with Lufthansa who treated us like royalty, and that was in Economy! The complete antithesis of the 747: a plane which has really had its days in terms of comfort for long leggedie beasties like me. The return journey was all 747 and I seemed to be cramped into a 24" space for 24 hours. So - Yes, I know what you mean. Choose your airline carefully is my opinion and then the aircraft. QANTAS is fine, but Singapore Airlines is fantastic. Oh! Don't forget the location of the seat. Check
www.seatguru.com for the best and worst seats. In other words do lots of research.
Then there is the season when it is best to visit. I have a very dear friend who lives in Cambridge, MA. She so badly wanted to come to Australia. She told us she would be coming for Christmas and staying for two months with my in-laws. December and January are months in which visiting the northern parts of Australia should be actively discouraged. We told our friend this but she insisted on coming. Australia does not have a gentle, mild summer. It is bloody hot and the heat unrelenting. I remember it being so hot one day that my glasses, which were metal, burned the sides of my face. Our friend had a terrible time with the heat and couldn't get back to Boston quickly enough. The best months imho, in Queensland, at least, are April/May and August/September.
A visit to NZ is an absolute must. It is quite magical, particulary the north island. Right up the top at the Bay of Islands, there is a small town called Waitangi, which is just beautiful. I loved the thermal activity of the North Island and the fabulous trout fishing on Lake Taupo which fronts three volcanoes. You just have to go there. If you visit the South Island go to Queenstown, much of the Lord of the Rings was filmed there.