I used this website recently to get a quote for medical insurance and they have been really, really helpful, so if you like to do things online have a look and see what they can do for you.
https://www.inform.co.nz/overview/ They will check out what policies are available and advise you what they think is best, and they seem pretty unbiased here and give down to earth advise, send you all the info by email and once you narrow it down more info and application forms by post which you fill in and send back to them and they go from there.
Ali
x