The Asus Xonar cards you linked don't have optical input? and the HT Omega Striker appears to be unavailable in Australia also it is PCI not PCIe.
I think I'm going to go with the Creative X-Fi Titanium PCIe, seems to be everything I need at a reasonable price and available in Australia.
Anyone else have any suggestions or ideas?
If you prefer digital connections, the DX's S/PDIF output is shared with its analog line and mic input port. A digital S/PDIF input port isn't provided on the port cluster, but the card does feature a four-pin auxiliary input connector.