What about international bank drafts?
If you have an overseas bank account, another option is to get an international bank draft sent to your Australian bank account. With this option, you can use your money with one financial institution to get a cheque written up in another currency.
This type of bank cheque is widely accepted around the world and offers more security than regular cheques. When you get an international bank draft, the money is taken from your account at the time it's issued, which also means that there is no risk of it bouncing. The downside is that it can be expensive and slow, with international bank drafts typically taking several weeks to be processed and cleared.