Does anyone know of boards like these designs that are for sale in Australia?
From reading up on the topic, these style of boards seem to be the best for whitewater river surfing but they don't appear to be for sale anywhere in Australia.

coloradokayak.com/pages/boats-boards

http://www.airhead.com/watersports/sup-boats-kayaks/sup/ss-stand-up-paddleboard.html

The Badfish one seems incredibly stable from the youtube videos.

do you mean one of these??

They do look similar. I'll give you that.
I wouldn't mind some padding for rocks in whitewater though!

We have a Starboard Stream in stock it is 9'6" x 36" and retails for $1,785.

If you are local pop in and check it out, if not ask your local starboard retailer about them.

Check it out on YouTube, the action is at the end:-

Thanks - they look great! I am not local but thanks for letting me know about them.