Erm I dunno what brand they are Marv but they are in Kgs. 0.5 is the lowest I have.
I bought most of my small plates at Be-Fit sales and hire here in Adelaide.Pretty cheap although I cant remember the price now.
Her4es a link to their site
http://www.befit.com.au/
Im not sure if you can buy online or not but I see they have outlets in Melbz on their site.