I don't know exactly were in NZ you will be, but just bare in mind that in the Southren Hemisphere, it is now spring, but still fairly cold at times.
These are the basics that I learnt:
underwear:
nothing to add
Base layer:
unless you are going into the higher altitudes, I don't think thermals are neccesarry. A vest is an idea, as it can get quite hot in the aftrenoon
Mid Layer / Evening wear:
i'd add a simple tracksuit for just lazing about in.
Windproof / Water Resistant:
I'd add gloves and a beanie
Polar fleece is my choice of material for this layer - Windproof, waterresistant, and good insulation
Warm and Waterproof:
I prefer to call this the "shell layer"
This is my chioce:
A haevy breathable (goretex??) jacket and trousers. your warmth is covered in the mid layer section. if you expect colder conditions, a downfilled parka goes under your jacket, and your trousers should be lined with fleece.
It is difficult to give a detailed opinion, as I don't know the exact conditions you expect to encounter. being at a similar lattitude to New Zealand, I expect the weather conditions to have some resembelance to the current conditions in Cape Town. Do a bit more research on the expected weather conditions, and try buy clothing that you will still use after the trip.
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'n Boer maak 'n plan
WOFT