It's always advisable to focus on a list of around 10 casting directors or casting offices that currently work on the shows or productions that you're most interested in. You can use sites like CastingAbout.com or IMDbPro.com to do your research, and then use Acting Resource Guru to find where they teach and find the best location and price for your needs.
PLUS - ARG Pro Members get an exclusive deal with CastingAbout. You're welcome. 😏