Hi, I'm also from Brisbane. My two guineapigs came from the Australian Cavy Santuary.
Bunnings Capalaba has both the ibex (5 pack - $11.50) and the rubbermaid (12 pack $25) grids. They are in the same aisle, but not next to eachother. Used 3 of the rubbermaid packs to make my cage, they are...