I think Steve is the ONLY Aus supplier now:
http://myastroshop.com.au/products/d...p?id=MAS-033A4
Steve says 5kg load.
I have used the GSO/Bintel copy - it's carp. Everything had a habit of loosening without any input, and it tended to slip... and that was with a Skywatcher ED80 and a Tak FS60!!!!! (separately, not together) The Vixen version is a LOT smoother and steadier. The GSO/Bintel copy is a fair bit cheaper though, but cheap comes at a price.