Indeed. While they are common in the US, it seems that your country prefers the white plastic stuff. The only problem with ordering them from the US is I'm not sure if the mounting holes would be compatible with your devices.

"I'm not sure if the mounting holes would be compatible with your devices."

Surprisingly, they might be compatible. I found this diagram at https://www.auselectronicsdirect.com.au 

My ruler says that the standard US device mounting yoke ears are on 84 mm centers. So if the 84 mm dimension above is the box mounting centers, it might indeed fit. You'd have to double check the external dimensions of the devices against the internal dimensions of our boxes (which vary), but I wouldn't be surprised if you could find one that would fit your devices.

Another potential problem is that US "handy box" knockouts for connectors or conduit fittings are mostly 7/8" (22 mm) or 1-1/8" (28.5 mm), to fit 3/4" and 1" adapters. Your 20 mm conduit might fit the 7/8" knockouts, but you'd have to measure to make sure.

Also, while you probably could get Australian devices to fit US boxes, if you can't find metal-faced devices you're kind of stuck. Our cover plates have a completely different format from yours. I guess you could buy a blank metal plate and drill and punch it to suit, but what a headache! And the decorative metal US blank plates come in fairly limited sizes, from what I've seen.

The issue might be moot anyway. I'd be very surprised if US-standard junction boxes and covers would be approved for use under the Australian building code.

PS - I kind of like the switches I see on at least some of your power points.