charlie s charlie has some good gen here. I have flown with two of those companies and visited a third. Very professional operations.
One point to note about Australia as has been mentioned before is that although it is a big country, the helicopter industry is a village. Everybody knows everybody elses business, so it doesn't take long for a shonkey operator to get found out.
CASA don't always get there first, it is often the lack of students and the high insurance costs after a couple of prangs that kills the dodgey schools.
To charlies list up there I would also add a new company in Bankstown, Helicopter Transport and Training who are doing everything right. Professionalism in spades, and the price is fair.