Just returned on Saturday from Port Douglas. You will definitely want to fly into Cairns for the GBR. Virgin Blue had pretty good prices on fares from Sydney and the flight take about 2 1/2 hours. We spent most of our time in Port Douglas which is a smaller village about 45km to 60km north of the airport. Nice location to GBR and Daintree from the town and some good restaurants. Can give you some recommendations if interested as well.