Hi there mate, Nikki Kelly here. I have a few ideas for your holiday. If you are looking for a cultural experince then come to Rotorua North Island, alot of Maori tourism for the three days off the river, brilliant mountain biking lakes, ocean ect. For the three days on water you have the Rangitike, Kaituna and Wairoa, as much Gore Canyon as you can handle. but the down fall is you may have to hire a guide, it can take three days to meet the right people to kayak with or sort our vehicles ect. There is the local kayak shop www.sunspotskayaks.co.nz
to hire boats, and www.multidayadventures.co.nz
if you have a little extra cash and want the best 6 day cultural, activity kayaking holiday wicked company i work for them.
Other option, the stunning south island, straight to Murchison, always plenty of people to kayak with, nz kayak school to hire boats, all the sections easy grade three NZ style. Good vibes down there.
hope it works out, post anymore questions
nikki kelly team D