American contemplating a move to Mexico City

Hi,
Can anyone give me names of housing complexes used by expats in Mexico city? Also concerned about safety for my family in Mexico City/Mexico. Can anyone address issues regarding safety? How is the International School? American Foundation (school)?? Anyone want to give input regarding overall expat life in Mexico City that would be great. If anyone is familiar with a gymnastics training center (my daughter is a competitive gymnast) in Mexico City that would be great information as well.

Thanks,
Lisa