I know just a little bit about the Tupis. They were excellent jungle-fighters in Portuguise Brazil. Apparently, they may have engaged in ritualistic cannibalism. Here's a nice "showpiece" of Native tribes in the Americas, the Tupis are at the very bottom:
http://aoe3.heavengames.com/gameinfo....shtml#natives
If you have trouble getting here, let me know, the tribes are in the bottom half of the page.
Since I borrowed it from a Civilization link, it even lists some appropriate units for each tribe-an added bonus.