Cadpat is everywhere, easy as pie to get as far as I'm aware... though it could be just repro is easy to get... I'm not 100% on the availability of surplus, it's likely out there, and if not now, it will be when you come to visit.
Are full auto AEGs really illegal in NZ? By your post I'm assuming you can still go semi...
Welcome to ASC
"War must be, while we defend our lives against a destroyer who would devour all; but I do not love the bright sword for its sharpness, nor the arrow for its swiftness, nor the warrior for his glory. I love only that which they defend: the city of the Men of Numenor, and I would have her loved for her memory, her ancientry, her beauty, and her present wisdom. Not feared, save as men may fear the dignity of a man, old and wise." - J.R.R. Tolkien