Sorry chap, can't really comment on how the system works dunnunda but have you considered applying to both the RAAF and the Uni's and see what offers you get. If they both offer you a place then you've got a decision to make, if not you can continue with the path left to you.
Best of luck in whatever you decide to do.
PS if you post a similar thread on the Godzone and Dunnunda forum you may get a better response from serving or ex oz fast pointy mates.