Your post compelled me to grab my little Quad Band unlocked GSM Motorola V188 flip phone and cheat sheet from its box. I can tell you this. Telcel is definitely a GSM carrier. In Mexico the GSM providers are Telcel and Movistar. The CDMA carriers are IUSACELL and Unefon.
I am not totally hip to the science behind 3G however I've seen videos and read articles regarding 3G services being obtained operating on the Telcel network. You would be best served by dealing with a guru who lives and operates cell phones in Mexico.