I don't believe there're specific restrictions on Cuban cigars as such. In terms of allowance, try this:

http://www.dutyfreestores.co.nz/Allowances
http://www.customs.govt.nz/traveller...nd/default.htm

Alternatively, ask our friend Google.

In terms of food and stuff like that, NZ is the same as Australia in many aspects. Any food, plants, etc, declare it. Anything you aren't sure, declare it.

You can also buy duty free on arrival in AKL. I suspect most items will be cheaper in AKL than in SYD. Having said that, the range on arrival is likely to be smaller than at departure. Again, ask our friend Google.