Captain's generally stocks the charts published by the government of New Zealand listed in this department. Others can be ordered for you -- allow three weeks for special orders. If you know the chart number you want you can enter it in the "key word" search to go right to it.
CLICK HERE to view the interactive New Zealand chart catalog, which offers preview images of the charts themselves so you can verify the coverage you want before ordering. If you need a printed copy of the New Zealand chart catalog a pdf file is offered on this New Zealand site which you can download and print.