I just had success using jobseekers.com.au
Try not to be to disheartened, there are a high volume of applicants for most vacancies. I applied from England and never got one reply. As others have said, Its difficult when your not in the state.
You will find out when you get here but in my experience so far, companies don't waste time dilly dalling about like they do in England. Once decisions have been made wether it's a job or property things move very quickly here. (One of the reasons I love SA.. No messing about)
All the best