6 weeks in NZ with 7 month baby

My husband and I are travelling to NZ for 6 weeks with our 7 month baby.
Do you have any suggestions on how we should plan our trip and what to see? And does anyone have experience travelling in NZ with a baby. Is there anything we should avoid or be careful with?
Are there any equipment that could come in handy - ex. if we want to go trekking, sail etc.
We are thinking on renting a campervan and drive around.

Thanks a lot for all tips on how to plan our route!

Cheers Sanna

That is a pretty open question, your starting point would be a NZ guide book like the Lonely planet guide, Rough guide or footprints

We spent a month travelling in NZ with our daughter when she was 5 months old. We took our own car seat which then stowed as hand luggage - you would need to check if this is still okay. It was great for keeping her comfortable at the airports and when we hired a car we knew she was safe. When you fly make sure you get a bulk-head bassonette for the baby, makes a huge difference.
NZ is easy and safe for travelling, can't think of any problems that we had and if you have your own accommodation on wheels it should be even easier. Too much to do and see to describe here. If you trek I guess a decent babycarrier would be a good idea, we severley modified our activities, but still managed some walking and exploring and had a great time.
All the usual baby stuff easily available out there. Have a great time, if you think of anything more specific I'll try to help.