Could I make the following suggestions regarding your training since you are planning to fly in oz once you have your NZ CPL (H).
Complete your training with as much Pilot in Command time as possible.
Make sure that all low flying that you do is specifically logged as low flying and if possible get your instructor to indorse you logbook saying that you have completed X amount of low flying hours (ideally the amount required for the aussie low flying rating)
Obtain a H300 and R22 rating within your CPL training to minimise costs.
Contact CASA now and check out what flight experience you need for the aussie CPL and make sure that you cover all of the CASA CPL(H) requirement within your NZ CPL
Also in addition to the above don’t get pressured into flying and not logging hours once in the mustering scene. Not a good start to your career.
Good luck!