I put my vote in for the Kobo e-reader.
First of all the iPad is a nice "gotta have it toy" but the glossy screen makes it unusable a lot of situations.
The Kindle great for reading, however the e-ink screen is currently on so many devices that it is a moot point. My main issue with the Kindle is that when you purchase a book you don't actually buy the book, what you are buying is a license to read the book, which can be revoked at any time. In addition Amazon is big, but what happens to the books that you purchase should they decide to stop selling and supporting the e-book format. You are left with a bunch of files in a proprietary format that are basically unusable.
With the Kobo reader you are actually purchasing the book, you can get it in multiple formats in which you can choose some or all of them. If you so desire you could even print the book with your printer and physically read it. You can use their reader, you can down load the app for your cell phone (or iPod touch) to read it there, you can read it on your computer. If you so desire and you go ahead with the iPad you can download the Kobo app for that.
Of the two I say iPad, if you go with the iPad don't use the Kindle app, use Kobo (or if you must use iBooks), but anything but Kindle.
If I can throw in my opinion go with the Kobo reader, it is straight and to the point. And I know for a fact that the Kobo is available in Australia.
*full disclosure, I work for the company that owns the majority stake in Kobo,