The orpinton has a heaver body, more rounded out and stout. The Australorp has a more streamlined body. Check out pics on the web and you can see the differences.
I'm thinking Black Austrolorp roo, too.
"Bottom of the feet are almost a buff or flesh color, (would that be considered white or yellow?)"
I'd say that makes them white.
Be careful. These days you can't say flesh when refering to a light color, or buff. It isn't considered Politically...