No need to worry about anything in New Zealand. Most probably they can store some stuff in any backpackers hostel around New Zealand. Been there three times and the folks there are one of the most helpful, honest and hospitable people I`ve ever met around the world.
They are looking to work while in NZ, any suggestions on where they should begin their search?
They will get all their needed directions in the backpackers `scene` (hostels etc.).
They'd love to work in a vineyard
There should be some work in a vineyard, but I guess due to economics crisis (`n stuff) they might not have that much choice in work possibilities as they might have some years before, but in general, they should"at least" get a fruit picking/ farm hand job.
I'm envious of their adventures. Luckily they blog and upload pictures
A link would be nice

New Zealand is great. Although I have to admit I missed the german prices for beer, wine and booze.

;)