Hi,
I am a Kiwi, and have visited most spots. The Volcanic activity spots in the Nth Island are pretty neat. Like any holiday it is the unexpected that can be the most exciting. To see the best stuff you would have your own transport i would say but that could be costly by yourself.
I am from the very South and the mountains, glaciers, native bush/national parks and farm plains are pretty decent.
‘Laser guided’ trip could be interpreted as ‘pretty much the tourist spots’.
Epic camp is doing a cycle trip from the top of the North Island to the bottom of the South this year, and that would be a good way to see the countryside and meet some locals.
You are welcome to ask me any specific questions here.