I know Square 1 puzzles are easily available in the US and Canada (made by Irwin toys).
2 or 3 years ago Irwin toys had a "so-so" web site, but since they have been bought up
and the company presence on the web is limited. (the web site isn't very good)
You can see on this web page a map of Canada, the US and Australia (only the US map is "linked")http://www.irwintoy.com/other/prods_games.html
However if you wish to send them an e-mail go to this link:http://www.irwintoy.com/other/contactus.html
If they don't respond to your inquiry, you could always look into the Rubik's distributor in Australia
...I know the Square 1 puzzle isn't a Rubik puzzle but maybe the distributor knows who,
and where you can find them?
Name: Crown and Andrews Pty. Ltd.
Address: 19 - 21 Euston Street
Rydalmere NSW 2116
Phone: 61 2 9898-3555
Fax: 61 2 9898-3155
Hope this help a wee bit !