You'll find plenty of ex-pat poms here to welcome you to these fair shores, congratulations on deciding to make the move!
As aquakiwi has said, Beachat gear is thin on the ground - popular in the spearfishing community, which is mostly breath hold here, so fins, masks wetsuits etc are common enough, but I don't know of any reg service technicians.
Aqualung fine, almost everywhere will service Aqualung regs. Scubapro also worth considering, as plenty of places stock and service Scuabpro. I find Apeks is a little expensive in terms of servicing here.
The big question regarding wet/drysuits is where are you actually moving to? Even in the deep south, most Kiwi divers stick to a 7mm wetsuit all year round, but then they are a difference breed down south! Up here in the north, water temperature will generally vary from 12-14 degC in winter, through to 20-22 degC in summer. I am a big jesse and dive my drysuit all year around.
Down in the south, you're probably looking at between 7-10 degC in winter - unsure of summer temps, but I'd guess it may only reach the 16-18 degC range?
If you already own a drysuit, I'd bring it for sure.