I've used BAX Global to ship lots of different stuff to Oz. I happened to be on the phone with them and they require a wheel/tire combo to be deflated and boxed or crated so its unlikely that Tire Rack, Discount Tire, or the other US suppliers will be willing to ship directly.
You can have them shipped to my shop and I can box or crate them up and send them via BAX. I'll have to charge a couple hours of my time to source the boxes, package, etc. I don't make money on the shipping so my actual costs will be what you're charged.
Having raced on the R1s I can say that they are not anything really special. If you can get the 710s or the Hoosiers those are better tires. The Toyo R888 is about the same as the BFG R1.