Another Aussie user here (well my wife is the user, I'm the fixer - I can't get near the reader just for a read).
If you have your own content and need to convert it, tag it etc look at Libprs500. It works really well, especially converting microsoft reader (LIT) format. See the wiki entry here:
https://wiki.mobileread.com/wiki/Libprs500
I haven't activated the reader or looked at the Sony store. Charlieperry, I'd be interested to know how you claimed your free books - did you just activate through the SonyConnect software and go to the store?
If you are thinking of buying from the US, B&H Photovideo will sell one to you. They are a reputable store and very quick.
http://www.bhphotovideo.com/