One site you may wish to check is www.audioenz.co.nz
It claims to be NZ's most read hifi magazine and gives some indication of the types/brands of available equipment. Of course, New Zealand does produce some of its own high-end gear - Perreaux (www.perreaux.com) springs to mind - so if you decide to sell your current gear you could always go native!
I'm actually located in Australia so feel obliged to comment on a previous post on Australian tariffs. We actually have pretty low tariffs, around 5%, and now that we have a free trade agreement with the US those tariffs have mostly been removed (except on products like sugar, where you guys insist on protecting your inefficient producers!)