I went out there quite recently and wanted to have a go but it required quite a lot of paperwork unless you had a hunting contact who was living there, andas my trip was last minute I wasn't really able to do much about it.
Guided trips/safaris were really expensive, and they are totally anal about gun laws even airguns are on an FAC!
I think you have to sort out your import papers several weeks before you arrive so check it out carefully.
There are some great areas of wilderness where you can hunt I looked at Victoria Natinal Park as a place I intend to go to next time
There are a few links below to Aus Hunt website and the State Park Hunting Links, hope this helps