Hmmm, might be difficult to find online. I recall not being able to obtain much and even entertained getting some set across the country from Perth to Brisbane.
I managed to get some from a wreckers, but it was about 150Km away.... From memory the calipers are the same as those found on a Pintara; so maybe just check you local wreckers for anything available. Also, I recall having to buy the caliper mounting brackets as well, came in handy when adapting them to the Atlas axle...
Also, where are you located? Perhaps other members can keep an eye out in their local cities for you. I live in Canberra and can grab any if you're interested.