Janel,
In Australia you should try Clark Rubber. They have locations throughout Australia and I think they sell both reticulated foam and polyfoam. The reticulated foam is likely sold as filter foam, but the best thing to do is go in to a store and see if you can get a sample or at least see it in person. The challenge with foam is that it's usually manufactured slightly different in different places, so what you get in the U.S.A. might not be the same as what you get you Europe or Asia.
BTW, if you search online for "Australia foam suppliers" you get an entire list of companies that sell different types of foam.