Of course, go to NZ! I've been there around 7 times, partly due to family connections but it's great anyway.
The Kiwis manufacture Anti-Jet Lag tablets, which are available in a small package at Easygoing, my travel bookstore in Berkeley, CA (and doubtless other U.S. travel stores). They use 5 herbal ingredients, not nasty chemicals. Going 8 time zones to Europe, I've found them pretty effective. Contact me if you need further details.
Enjoy the trip!