+ 1 for the calling TCU suggestion
I previously lived in Adelaide and used to fly from Adelaide and Parafield fairly regularly. Usually I had a pretty good run at whatever scenic or practice approaches I was looking to do. I almost always had to book a slot (which you can do over the phone when you speak to them)
The coastal offshore route is fun but often you'll be kept down to 500' and may need to hold a number of times. It you do end up doing it I'd look pretty carefully at which jetty is which - the instruction will be something like 'Orbit offshore at Grange Jetty' and if you're not familiar with Adelaide it would be pretty easy to confuse yourself!
Have fun!