You are in good hands with Mark Law/Frontier. One of the most respected instructors in New Zealand and one of the even fewer that will help you into a job at the end of your training. As you have identified, job prospects are not good in NZ and I can give you a list of about 10 recently graduated CPL pilots who are all trained up with no where to go who will confirm this for you...
If Whakatane and Frontier don't work out for you then I think North Shore Helicopters and Heliflite in Auckland are both NZQA accredited meaning they can help with foreign students and visa's etc.
Contact people are:
North Shore Helicopters, Roy Crane
[email protected]
Heliflite Charter and training, Alex Justice
[email protected]
Both are good schools with decent instructors and safety records.
I haven't trained with Mark Law but most of the NZ Helicopter industry have great things to say about him and his training. I would have liked to do some flying there myself but needed to keep it local in Auckland so I could keep working to pay the bills.
Good luck