Hey Mate
Tamyia paints, incl. their sprays are readily available in most LHS, such as Perth Hobby Centre in the City, Stanbridges, etc, and in most (not all) toy stores like some Toyworld outlets. You should have no problem finding them. The link to the Perth Military Model Directory is excellent and I always refer people to that.
Needless to say, I come from Perth; so enjoy painting in Perth!