I can answer one part of your question - how to ship it home....
Look
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Given a couple of hours I'm sure we can come up with the rest of your answers.
More Info from the bottom of the above 'page'....
New Zealand
How can I find out info on what the Duty/GST costs will be for importing into New Zealand?
GST is payable at 12.5% on the landed value, which is the value of the vehicle, plus freight, plus insurance. Otherwise known as the CIF(Cost+Insurance+Freight) price.
If you are to be exempted from GST you need to meet the following conditions:
Be a first time immigrant or a returning New Zealand citizen.
If a returning citizen, you must have been our of New Zealand for over 21 months.
Be prepared to sign a deed where you agree not to sell the vehicle for at least 2 years.
Vehicle must have been owned and used for last 12 months.
…and you must provide the following documents:
Proof of ownership over the last 12 months
Proof that you are taking up residency in New Zealand, e.g. bank statements, letter from future employer, etc. (must have 2 documents)
Where can I find out information on New Zealand road compliance?
Visit the Land Transport web site factsheets.
Are there any restrictions on the import of this particular vehicle?
There are no restrictions on importing vehicles into New Zealand, however it is up to you to ensure any legal implications or compliance's for New Zealand road use.