... Importing them isn't an option either. Only Aussie has the same frequency as NZ and they are more expensive by the time you import.
Is it that the US frequencies won't work here or just that the frequency they use isn't approved for use in NZ?
It's been discussed before. They are using licensed frequencies and if you are caught there are big fines. Don't even think about it.
They will function, right up until you're fined and forced to remove them.
Cheers - N