I have been in contact with an APUG member from Dunedin, who has given me a lot of ideas and suggestions. I'm hoping to meet up with him while there. You are right, the South Island is one of the most beautiful places on earth. Most of the photographers from there that I know shoot mainly 6x17 - I'm going to visit Gilbert van Reenen a photographer from Wanaka that I bought a book from earlier this year.
What are of New Zealand do you live in? I've spent some time in the Otago and Milford Sound regions on my last trip, as well as a couple of days in Christchurch. Christchurch is quite a beautiful town, I could easily see myself living there.