Queenstown
I spent 2 weeks in Feb this year in the south Island of NZ on a pure DH and drinking holiday.
I took 7 mates and had the best time.
I would suggest you get in contact with Jono from QTB - Queenstown Bike Taxis,
http://www.queenstownbiketaxis.co.nz/ He can tailor make a trip to pick you up an cart you around between Wanaka, Queenstown or anywhere else you wish to go.
We flew to Christchurch and QBT picked us up at the airport and drove us to Mt Hutt where we rode in muddy conditions ( would have loved to ride in the the dry)
http://www.youtube.com/watch?v=y94HI1-VBio ..... Jono organized accommodation in both Methven (Mt Hutt) and Christchurch.
We then drove to Wanaka where we stayed in a big house that was cheap, I think it ended up being $370 per night for 8 people. It was a little out of town but he was walkable into town, esp after 15 beers.
http://www.hotelscombined.com.au/Hotel/Pisa_House.htm
Jono took us to Snow Park (Cardrona)
http://www.youtube.com/watch?v=gHy1dpBsMrc .. After 1 days riding in Wanaka and 2 crazy nights out on the town. Jono picked us up and drove us to Queenstown.
We stayed at the Glebe - in the coronet penthouse which between 9 for 8 nights was about $50 each per night.
http://www.youtube.com/watch?v=wgVXmgH8c5U So close to town, plenty of storage for bikes and 2 car parks. We ended up just keeping the bikes on the balcony, No dramas with the hotel. Best views!
Jono picked us up for shuttles at zoot track and wynyard trails - Well worth it, sick tracks for all skills.
http://www.youtube.com/watch?v=iZPw9zZ0BDY &
http://www.youtube.com/watch?v=aH4cOCHUurM
The other days we road the gondola - Half days were enough, unless you are hardcore.
Jono picked us up from Queenstown and drove us to Dunedin for some sweet sweet trails, stayed the night in Dunedin and then again in Christ Church before dropping us back off at the airport.
I would strongly recommend you get in contact with Jono before you travel and work something out.
As for hele drop, decided when you get there... I did it 5 years ago and loved it. Only reason i didnt this time was i was too sick to got in a helicopter (going out every night till sunrise will do that)
As for taking your own bike - if you were just going to queenstown I would hire one, but if you plan to ride more than 5 days and will ride places outside Queenstown and dont mind going through a set of pads every few days take your own!
And do some of the activites while there to mix it up, we did the Maddog river boarding and was heaps of fun.
If you or any one else looking to travel to nz for a biking holiday just give me a Private message and I will try and help you out..