I think you will really struggle to find any availability in J for OZ at this very late stage. Might I suggest that you check the route finder on Staralliance.com and include searches for routes between likely intermediate points. You could then try ANA,Continental and Aeroplan for availability. You might find availability to or via otherwise unlikely routings e.g. there is often availability to BKK via DME when everything else has gone. It is unlikely that there will be any/many? J seats released for the dates you want at a late stage as they can generally be sold for big bucks! If you could find a flight to Asia you might want to consider a LCC flight to Perth on such as Air Asia. The one possible return date might be 31 December, not a popular date to fly on. Hope this is of some help.