WestTxAg12, sorry just now seeing this! Several of us are trying to start an Aggie group here. We hope to have a couple more events in the fall to keep growing the interest. Look up our Facebook group, Mexico City Aggies for more info when you move here.
Also, the best advice I can give on places to live is try to live pretty close to where you work. Traffic can be pretty terrible and it cuts down on the stress. But Polanco, Lomas and Santa Fe are a good place to start. Best of luck, its a great city!