The Australians originally came from Afrika Korps. If you can't find that on eBay or some after-market shop, like
Noble Knight Games, your next best choice is Parachutes Over Crete.
The Japanese came from Guadalcanal. If the secondary market comes up short, get Saipan'44.
One more little thing. The 10th scenario has an American AA unit. You will need American counters from somewhere. the 40mm will be the biggest problem, but the British have one in a pinch.