I don't think kiwi employers are in the habit of searching themselves, unless they really cannot find someone after months of trying. They often rely on their own networks first, then advertising. Getting a job offer prior to arriving in NZ is incredibly hard and takes a lot of hard work and determination from the applicant's point of view. Many employers aren't even willing to consider an applicant from abroad for fear of them being time wasters.
I'm not trying to be a nay-sayer, but I'm trying to ensure your goals are realistic. I don't know anything about your profession and the shortage (or not) of those skills in NZ, but even when there is a shortage, it is often hard to convince employers to take a leap of faith and employ someone who doesn't even live here yet. They are also unlikely to come looking for you.