Really depends on how much weight you are willing to lose to the bag (vs contents). My main carry-on is a Herolite 55cm 2 wheeler that's 1.5kg. So it's quite a delta in weight.

Hi, I'm trying to figure out the best way to get to and from South America from Melbourne, within the continent (circa 8 countries), and within Brazil for WC (4 cities). I have ~400k Qantas FF points, and have heard about the OneWorld South American explorer, as well as TAM explorer around Brazil...