Pretty late in the season to be looking for garlic. Chances are that anything not sold out has been / will be planted. The only people who might still have some Pyongyang would be SSE (they list it in their members-only catalog), but even that is unlikely, since SSE plants its garlic in October. Pyongyang is an Asiatic type; you might have better luck with other Asiatic varieties. Japanese (a.k.a. Sakura) is one of those; larger & probably milder... and I believe some members here grow it (I plan to add it next year). Korean Hot is another possibility.

I looked around; you might want to try this site, since they appear to still have Pyongyang:

Garlicana Asiatic garlic

Garlic looks as appetizing as possible.