The Information Technology Association of New Zealand's website has this page of answers to FAQ's which will interest any IT contractor looking to move to NZ. 

FAQ's dealt with include

Is it necessary to hold a job or job offer in NZ before applying for a letter of support?

Do I need to have a degree to apply for a Letter of Support?

How many years of work experience in IT do I need before I can apply for a Letter of Support?

If I am a contractor in the IT industry, can I apply for a Letter of Support?How many years work experience does the 10 points I receive for the Letter of Support include?

For the ITANZ's answers to these questions, follow the link here