I bought all my cubes from Bunnings, Narre warren, and Morwell in VIC.
It was about $12.95 for 5 grids...A little expensive but owell lol.
I got my Corflute from Australian Visual Solutions in Dandenong South, VIC. (Type it in google, easily found).
It was $16 per 6x4 sheet, it is 3mm thick and they have blue, black, green and yellow (No red )
I hope that helped some victorians!