I think the front-runners are definitely most likely, no doubt.....Portugal, Zulu, Indonesia, Native American civ, Kongo, and Brazil
Those sound pretty solid, the rest are toss up iffys
I'd argue that Brazil is pretty iffy. Mind you, I'm not saying it would be a bad thing - would be a nice representation for the more modern side of South America - but I find it rather unlikely, given the tendency to avoid the region and the tendency to avoid colonial states.