I'm imagining some sort of "sea caravans" with many boats sailing from modern day Ecuador and sticking close to the coast until they arrived... where?, in modern day Michoacán?, Oaxaca?, somewhere farther south?

And once there... how did they communicate?, were there quechua translators in mexico?, or did nahuatl translators accompained the traders?. Also, I've heard that people in Mexico bought mostly copper from the southamericans but, what did the south americans buy?