I highly doubt that you'll be able to get any gars in Australia due to the extremely strict importation regulations. If you can find a gar for sale that looks like a spotted gar, then it's most likely a Florida gar rather than a spotted gar.
theres a few fish floating around now, silvers, florida gars, rtc and shovel nose and a few senegals. try canley vale or SLS, they usually have something floating around