Well, ideally, I think you could look for events in your area that allow you to met women from your area face to face. Then you can meet them and they can interview you and write the recs. You might be able to find out these event from one of the alumna contacts or from a local NPC group.
Have you already figured out which of the women that you know in real life are members of sororities?
ETA:
http://www.npcwomen.org/alumnae/a_directory.php
If you go to that link, you could look for groups in your area that might have events.