Go to www.blu-ray.com which is an official website for release and review of ALL Blu-Ray movies, when you enter a movie's name, you can see the pop up options for all version of it. If there was an Australian version, you can find them by a sign of national flag. Then you can know the cover and the image of that version.
Actually there are very few Australian version of Blu-Ray movie, also, Australia is in the same Blu-Ray region with UK so it is really not important to buy a so-called "Australian release". The UK version is very good for Australian user, they are genuine, they are original, and most importantly, they will not cost you too much.