fly girl, Skytrans and hinterland are at the top of the food chain in terms of GA companies.
Skytrans pay award wages + allowances. They have C310's, Bongos, titians and a kingair. Get to live in cairns although when you first start u basically do 2 weeks per month (roughly) on horn island, until you move up the list of pilots
They basically take people who are coming out of the bush looking for somewhere nicer to live, waiting for an airline job
Hinterland is pretty much the same but operate different aircraft and have a caravan I think - but could be wrong. I have been told they are good to work for.
GAM is also another tope GA company with similar pay/conditions. I know Gam don't care if your a chick or a bloke.
As far as the others, no idea
Cape york - don't know anything about them
yigy2