Hey Meg!
I saw that you asked your question back when GC wasn't registering responses and bumping up threads, so no one ever knew you asked a question.
Not sure if there is a book with a compilation of A*Phi designs, but that would be a good idea for someone to put together. Perhaps for a fundraiser?
Here are a few options to add to the ones previously suggested above:
Top Cross Stitch Sites
Sorority Angel
Sorority Specialties Crest Cross Stitch
Crest Cross Stitch
Mascot / Symbol Cross Stitch Kit
Sorority Cross Stitch Kit
Free Greek Letter Patterns
Beautiful Forget Me Not Pattern
ETA:
PM UWOAPhi for a pattern book