You could try your local Glazier. They regularly deal with aluminium suppliers like Capral http://www.capral.com.au and others. While they wouldn't have these mouldings on the shelves themselves its likely there could order it in for you from one of there suppliers.

I'd also try your local joiner/cabinet maker. They'd also have suppliers who'd be likely to make this stuff.

Or these guys might have what your after.
http://www.oh-diners.com/divers/edge_molding.htm