Converting your EASA license into NZ equivalent is easy, also doing an Instructor rating should not be a major issue as you could do this with a Student visa. With your age you still qualify for a Work and Travel visa which buys you 1 year of work permit in NZ.
So the question you need to answer yourself is if you are ready and willing to spend the conversion and training cost in NZ. And as mentioned already there is already an over-supply of instructors in this country.
Good luck!