McGee: Any new device into the country has to be accredited or telepermited by Chorus / Telecom.
See the bottom of your current modem and it should have the greens sticker with the tick.
From memory it costs some horrendous amount to get them telepermited.
Ah, I read your "won't be telepermitted" to mean that it will not be because it cannot be.
According to the Chorus telepermit site, its already got it:
279/11/006 AVM FRITZ!BOX 7390 DSL Gateway/Router