Where can i get 35mm slide film in Brisbane? (AUS)?

Actually, it is rare for a Film Developing shop to have slide film.

Browse your phone book and look for "Pro Camera Shop","Camera Repair Shop", etc. Something a bit more technical.

Also, call a portrait studio or wedding photographer. They will shoot digital today but they can probably direct you to some slide film.

Any photo development centers that sells film.

The films are also known as positive films. You can also buy them here.
http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=2/3/9/7010/6994/1095&pq-locale=en_AU