Check the weekly Jobs Update page of the Australian Federation of Air Pilots website
www.afap.org.au
In the last six months Bristows have advertised for co-pilots at least twice.
As for getting noticed, I know absolutely nothing about the company culture or personalities, so this is general advice. Get your resume together (one page, licenses and flight time near the top), then call and ask to speak with the Chief Pilot. Explain that you'll be visiting in the vicinity shortly, interested in working for them in the future, and could you come in for a chat at his convenience? Most CPs will try and give you some time. Then it's up to you to make a good impression. Now at least you'll be a personality to him rather than a sheet of paper.
Of course, having a personal recommendation from a serving pilot will make a huge difference.
Good luck!