You can try using your existing profile.
Originally Posted by thirst
First thing to do is check the App Catalog. If it gives you a choice of country, choose the United States (unless you are optimistic, and think that they'll be giving us Australian paid App Catalog access... they haven't yet).
If it doesn't give you a choice of country, you can do a Full Erase, and create a new profile. It's not like the phones, where you get one shot at choosing a country and are locked in. Full Erase gives you a second chance.
(If I'm wrong, someone please let me know!)