How does the saying go...about clouds and silver lining? Tough economic conditions aren't all doom. Many New Zealanders have managed to hold onto their job, and still maintain a decent standard of living in the face of rising food and petrol prices. And these people are in a position to enter the real estate market and/or upgrade their home in a time of flat/reducing house prices and low interest rates.
Interest rates are tipped to stay at record lows till at least the end of the year. The current best offering seems to be from Kiwibank, who have just introduced their new 'Offset Mortgage' - with a floating rate of just 5.5%. And banks seem to be loosening their lending criteria again - with Westpac advertising 5% deposit mortgages on TV recently.
The best general source of information about mortgage rates in New Zealand is www.interest.co.nz which provides comparative rates for all the major banks and some not so major (heard of Kookmin???) in a simple table format. From there, you need to talk to the banks directly or through a mortgage broker.
Don't assume that switching your current mortgage to another bank for a small interest rate cut will make you better off - often the fees involved negate any small benefit. I personally went through this exercise about a year ago and found that switching banks would make me $75 a year better off - and decided it wasn't worth the hassle.
Interest.co also have what they claim is the best mortgage calculator in the world (http://www.interest.co.nz/calculators/mortgage-calculator). This allows you to start with either what you can afford to pay - to work out how much you can borrow, or what you want to borrow - to work out how much you would have to pay. As well as the obvious such as changing the mortgage term, there's also the ability to see the difference between paying fortnightly and monthly, and in advance or arrears. Seemingly small factors can make a noticeable difference to repayment amounts.
In the past, this kind of quality information has been 'smoke and mirrors' stuff kept half hidden and overly complex by banks (perhaps not intentionally). Clarity and quality of information should be the minimum one has when making the largest investment of ones life.