Bloody hell, Tim! Have you ever been to NZ before? Somehow I don't think so. I was born and raised there. Believe me, there's NOTHING you can't get/buy in NZ. Don't waste your time carting stuff over there other than those personal possessions which are close to your heart. With your strong UK pounds in your wallet, you'll be absolutely amazed at the value you will get. The only negative to staying there for a long period is that salaries/wages there are low, . . . so once you have had a spree with your UK savings, living it up and enjoying the most incredibly high standard of living, you could start to find things a bit difficult . . . unless of course you are going to be earning unusually high pay. But even NZ's doctors are quitting the country for elsewhere!
And, hey, man, you're going for an experience, aren't you? So buy yourself a NZ-made washing-machine, a NZ-made toaster, kettle, coffee-machine, and so forth . . . and while you're at it treat yourself to a brand new Australian-made car! (Mind you NZ's showrooms are full of excellent-quality reasonably-priced second-hand Japanese cars that consumerist aspiring Japanese no longer want!)
So let go, abandon yourself. And most of all, remember that NZ is a different culture . . . you won't be wanting exactly the same things you want when you're part of Blighty! If you do, then might as well stay here!
Eddy.