FedEx offers visibility and step by step updates on the status of your shipment. I don’t know the specific cost of US to Australia delivery.
If they buyer could be talked into this it would solve your problem because you would be shipping to the US. I’d mention it if the buyer is a frequent flyer of US auctions. There are a number of other companies offering the same service.
Crap. Check the aforementioned, but I this is probably the ticket:
USPS Priority Mail International:
Features
Delivery in 6 to 10 business days*
Reliable and affordable
Includes tracking information with our Track & Confirm tool**
May qualify for Free Package Pickup*** at your door
PMI
The track and confirm tool is your insurance for eBay.