thinking about it, Bundy and Lunchbox are right, unless you are school age or geriatric stay away from the Gold Coast etc. Its where people from the cold south of Australia retire. Yuck.
I believe Byron is great, they certainly make sexy swimming gear there
http://wickedweasel.com/oz/index.html
worth going there on the off chance of seeing one of their models or you could buy your g/f an outfit woo hoo, bark bark
If you are going north for the reef then you are better to fly direct from Sydney to Cairns and rent a van from there and forget Brisbane altogether
cheers