Hello, I am having major Customs/Duty/ GST confusion.

I have some items I will be sending from Kansas here in the US, to Auckland. The items are a mix of mostly new goods (cookware set, spice rack, wire shelves) and some "used" (bedding, blankets, shoes, picture frames). I will be sending these (possibly two separate boxes) to my partners address (his new residence). I will be arriving in NZ Feb 23rd, and I am not sure if I or the boxes will make it first. If I claim the new items as gifts to him (which is pretty much what they are, I bought him them in celebration of his new place), will there be duty or GST to pay? I read on the customs website that you are allowed to send $110 worth as gifts.
And as far as the other personal items of mine, I will be applying for a partnership based temporary work visa when I arrive, but not sure if that does much for me, or if I am allowed a certain amount of used personal goods for myself just as a vistor?

Im a little dense when it comes to these types of things, hey Im a first-timer so its allowed right?

If anyone can point me in the best direction of shipping these items so that I will be charged the least amount of duty/taxes/etc I would greatly appreciate it!

Thank you in advance!