As a non-resident, the licensing and purchasing process isn't too bad. Given you are on a finite visa, you will not need to get an Australian (whichever state) licence. However, you will still need an address to register the vehicle to.
To do that, you need to get proof of address - this can be as simple as a letter from an Australian bank (probably the easiest) or someone to sign a Statutory Declaration that you are resident at that address (I think this would work) - and present that along with a passport, driving licence and anything else that might be useful to get you to 100 points of ID.
When I first came to Australia 8 years ago, I used:
-Bank letter
-UK Driving licence
-UK Passport
-Bank card
to get my account set up. I now have an Australian driving licence, so it's all much easier...