You should contact Grassy Knoll. I believe Elizabeth grows it, but you'd have to ask whether she has it propagated and ready to go. She doesn't list all of her P. edulis varieties online.

Here is a link that might be useful: Grassy Knoll Exotic Plants contact page

Thanks, Mark! Elizabeth at Grassy Knoll was the way to go. She is shipping me Nancy Garrison and Black Knight!

Wow, great to hear that. Elizabeth is an incredible source of plants. I remember that as of a couple years ago, 'Black Knight' was Nancy's favorite P. edulis cultivar in terms of taste. So you can't go wrong.