Mexican-style ribs are fantastic! I almost always do a mexican-inspired rub for my ribs. Usually cumin, oregano, salt, pepper, some variety of chile powder, etc. For the sauce, maybe do something with either pureed chipotles in adobo or some chipotle powder. A buddy of mine makes Oaxacan bbq ribs that are out of this world. I wish I could get him to give me his recipe!