Great to hear of your plans. New Zealand is a great country for hostels. Travelled throughout for a year and that is where I got my love for hostels before starting my own. I visited Wanaka as well which is definately a great tourist spot. I would just be careful of the mindset that it cannot fail. Yes I understand your thought behind it but make sure you stay focused and work hard on what you are offering. You can still fail even if you are full if you don't have the proper business structure and pricing to keep the doors open. Have you started writing your business plan? Do you know what size of hostel and style of hostel you want to open? Would you lease or buy a building? Do you know the regulations for opening a hostel in New Zealand?