The Lord of the Rings Yahoo group has army lists for playing a Aztec v Conquistators variant.
In The Year of One Reed: Final Conquest of the Aztecs is a set of fast play rules for students about the Spanish conquest of Tenochtitlan.
Chronofus has written a guide to wargaming the Aztecs. This is a major work, with information on the various troop types, and comes complete with color illustrations
New World DBA is a set of amendments and lists for playing DBA games in the New World: Tupis, Aztecs, Incas and Conquistadors
Here’s a paper model of an ancient Central American style temple, just ripe for sacrifices. I think it would be terrific for a pulp action game.