Zimbo,
Have a read of your controlling bodies website. The URL link is:

http://www.nzmaa.org.nz/apps/

You will find that they have written a caution on the website against the use of many of the 72 Mhz bands in NZ and in fact they have withdrawn some 72 Mhz frequencies.

Apparently some 72 Mhz frequency's are also used by 2 way radios in the NZ logging and shipping industries. ( Crane operations etc)

Obviously the 2 will clash and for the modeller, the result will be more disasterous than for a guy chopping down a tree!

Save your self some long term$$$ (and heartache) and go with another band.

Do you know anybody coming over to OZ? They may be able to pick up a quality 2nd hand radio from Modelflite (the JR distributors here) at a good price. See their website at
http://www.modelflight.com.au/

But read the recommendation of your governing association and then go talk to your nearest club and see what they say. The URL has contact info on NZ clubs as well.

Best of luck and I hope you get flying soon.