Are you able to make some Australian players included in the database? Most likely as free agents though as the old NSL died off (The clubs aren't active in FM anymore).
If you have some spare time, here are some players!
Lucas Neill - Former West Ham and Australia captain http://en.wikipedia.org/wiki/Lucas_Neill
Brett Emerton - 247 games for Blackburn and 95 caps for Australia http://en.wikipedia.org/wiki/Brett_Emerton
Alex Tobin - Another former Australian captain and 87 caps, FFA Hall of fame http://en.wikipedia.org/wiki/Alex_Tobin
Paul Wade - 84 caps for Australia, FFA Hall of fame http://en.wikipedia.org/wiki/Paul_Wade
Tony Vidmar - 76 caps for Australia, 104 caps for Rangers http://en.wikipedia.org/wiki/Tony_Vidmar
Damien Mori - Second highest goalscorer for the national team, 334 career goals http://en.wikipedia.org/wiki/Damian_Mori
John Kosmina - 60 games and 25 goals for Australia, FFA Hall of fame http://en.wikipedia.org/wiki/John_Kosmina
David Zrillic - 25 goals for Australia http://en.wikipedia.org/wiki/David_Zdrilic
John Aloisi - http://en.wikipedia.org/wiki/John_Aloisi
Graham Arnold - http://en.wikipedia.org/wiki/Graham_Arnold