Hi there! Congrats on a great deal! I know the setups are extremely pricey down under so you got a great deal!
If I do my math correctly it's about 60 US gallons which gives you a lot of options. No tangs or anythign like that but still alot of fish and inverts will be quite happy in there.
I knwo they don't ship to AUS but have you checked out Aquarium Fish: Tropical Freshwater Fish and Saltwater Fish for Home Aquariums
They have a stupendous selection of corals, fish and inverts that can help give you some ideas. Also states whether things are reef safe and what other requirements the fish/invert/coral may have.
Good luck!! And btw, we LOVE pictures here so share some soon! LOL