Tent - free standing room appreciated.

Have you tried searching for Marquee on Google? I got nearly 600 entries in Aust.

I doubt that there would be anyone selling "off the shelf" canvas rooms that size. However you could probably get it made by Southern Cross.

www.southerncrosscanvas.com.au/index.html

Most rooms that size seem to be used by Party Hire companies.

I haven't seen one in real life, but you can get the 3x6metre and 3x9metre ones on Ebay. Do the "marquee" search. I'd guess that you'd get what you pay for.

Not sure what your application is, but have a look at this site.
www.bushranger.com.au/
We saw one at the Camping show in Brisbane. Rather than poles, you simply inflate it. Known as 'Blue Gum Inflatable tents'. Appeared robust, and the idea was brilliant............................Keith