I would say that the new 2009 Dobermann Molosse would be good for you. bmx spacing,light weight (5 pounds)24 or 26 specific and if you crack it ( i dont think you will) the guys at dobermann are super nice and great to deal with and will help you out. here is a link to there blog http://dobermannbikes.blogspot.com/2008/09/2009-molosse-mol-auss.html
+2000000000000
the only problem with a dobermann is that they may be hard to get in Australia but if you contact them i am sure they can ship one.
I Have good news for you. Dobermann Bikes will be imported to Australia pretty soon by our Friend Darren from www.brisbaneboutiquebikes.com.au
This will reduce the cost of shipping single frames and will give our Aussie consumers a much better service.