Both Ardmore Helicopters and North Shore helicopters are also incarnations of the student loan experiment too by the way. Not necessarily a bad thing I guess but in the interests of transparency.
I know a bunch of guys that have been through HFT and would never go near back if they didnt have to due to funding from the student loan. I haven't flown there so don't know from personal experience but that seems to be the consensus. Most of their gripes were not about the flying side of things but more just getting messed about with their courses and delayed.
I am Auckland based and am about to start a C-Cat Instructor rating too. I'm doing mine with Heliflite. They are Ardmore based and operate R22, R44 and R66. They have a really good deal on R22s and R44s for training at the moment and have A, B and C cat instructors. Have a look at
Heliflite ? Charter and Training | Auckland Heliflite Charter and Training.
Mark Law at Frontier Helicopters in Whakatane is also extremely well regarded. If you are heading to the South Island then Simon Spencer Bower in Wanaka is also a great option.
Unfortunately the NZ helicopter pilot job market is extremely competitive and very difficult to get into. Its not impossible but I wouldn't count on a job to do build hours after your instructor rating.
Also, to get your CPL converted you will need to add the NZ syllabus minimums to it. We have to do some mountain flying as well as a sling rating to obtain a CPL so if you don't have these already you may need to do some more training.
Good luck - most of the operators in NZ are good people to deal with, it would just be a matter of finding who suited you the best.