Hey mate
In sydney there are a few, including:
Bintel -
www.bintelshop.com.au
MyAstroShop -
www.myastroshop.com.au
Andrews -
www.andrewscomms.com.au
York Optical -
www.yorkoptical.com.au
Astronomy Online -
www.astronomyonline.com.au
I think that's most of them. I don't know of any that sell Orion gear except Bintel.