I've had the same problem trying to find Australian models, but with the added difficulty of modelling in N scale! Granted there are a few n scale producers, but I'm more interested in the modern era stuff and there is definitely a scarcity of those. So instead I turned to shapeways to made my own - which I think is the best way for modellers in small markets (like ours) to go about it.
If you're interested, you can check out my threads on making a CityRail Waratah and the Vline V'locity by Shapeways!