Hi Goofcat,
we rent gear (Axis boards and foils, PPC wings) pretty much anywhere in New Zealand. Our rentals work on a "rent like you own" system: You pick the gear up from us (in your case possibly in Auckland) and take care of it for the duration of your rental. You can take it anywhere you want in New Zealand and are not limited to one specific spot. No limitations on where, nor needing to return to the rental place in the evening before they close. Just as if it were your own.
For rentals, please book a few weeks in advance so we can ensure the right equipment is at the right place (as we operate nationwide).
Wingfoil locations:
It all comes down if you want to base yourself in one locations or go on a roadtrip and explore multiple areas.
As a starter, have a look at my blogpost "5 Flatwater Spots"
waternomads.co.nz/5-great-flatwater-foiling-spots-in-new-zealand/As kiwiupover already said, there is a good wingfoil scene around Auckland (with Auckland being the biggest city of New Zealand) and plenty of spots in any wind direction. However, a lot of those spots are city spots and not the most scenic ones (in my opinion). If you are prepared to get off the beaten track a little bit, you will find some absolute gems.
Raglan is a cute village with a big harbour to foil in (at high tide).
The Karikari Peninsula in Northland (Stunning scenery, captures any wind direction)
Kai Iwi Lakes (beautiful clear water, camping right at the lake front)
Or go and explore the countless lakes around Rotorua (with the added bonus of multiple hot springs in the area to soak those tired muscles)
Mount Maunganui / Tauranga has got some sheltered harbours as well, but you are limited to 1-2 hours either side of high tide (unless you know where the channels are). It's a buzzing party town, if you like a bit more nightlife and entertainment.
I personally prefer the South Island in summer. There are so many breathtaking places, it's less busy and the thermals work reliably.
Feel free to get in touch if you need any more info, we are traveling around the country all year round and know most spots.