Interesting idea - could work well. The flights from UK to (east coast) Aust/NZ are about 23/26 hours respectively, if done with a reasonable connection. So if your body clock was already at GMT+12, you'd essentially go through a full 24-hour cycle on the trip and arrive nicely aligned with the local time.
My thoughts precisely, so it's what happens when I'm aboard the plane that is the subject of this thread. Will someone who is already on NZ time be an issue?
or AirNZ via HKG or LAX (you can go either way around with AirNZ, or do a round-the-world).
Now that's an idea, but I probably won't be able to take a month off.
If you want to go via Aust, then Emirates would be your best bet, although Qantas will also work (if not on strike).
Ooh!
Let us know how you get on with the body clock synchronisation.
I'm still very much in the 'thinking about it' stage.