Being australian but having travelled extensively and examined many boobies both here and overseas I think I am qualified to comment.
Yes, there are many large boobies in oz. Some of the large sizing is due to boob jobs (god bless em), I know several girls myself with fakies. Some are just gods natural gift, I notice more big boobs here than on italians and greeks and asians but I don't think its a big booby paradise. Unfortunately as the oz lifestyle gets lazier, alot of these boobies are now big just because the girl connected to them is... big.
As for the hotness of the girls, oz is good, but the czeck republic is better.