JimmyConway - you're full of !!!!e.
6-12 months should see you with enough hours to apply to a regional airline along with every other piston twin driver in Australia.
1-2 years as a First Officer should then see you looking at a command. A further year as a Captain should see you competitive enough for a major domestic airline.
Sitting in the airline looking back at GA? Enjoy every minute. It's loads more fun, you do far more satisfying flying to far more interesting places.
A year on the Caravan certainly won't hurt you. In fact it may slow you down getting to a regional, but it will speed up the time to command once you are there due to turbine command experience.