I found the only way to get a Lynn August pot was to hang out at Bonsai Auctions or 99 Cent Bonsai Auctions, and the minute she posts a pot you like, hit the buy it now Price. If you try to wait out the auction for a lower price, someone will BIN before the auction ends. So if you see one, just snap it up, they go fast. Well, her smooth burnished finish pots really go fast. I'm not as big on the rough finish.
Similar or even higher quality than Lynn August, are pots by Karen Schumann, but she is more or less retired right now. She tends to fire very high temp, and has very thin walls for her pots. She does a similar smooth, burnished finish instead of using glazes. But her pots are hard to find, I haven't seen any for sale for a couple years. I did meet her about a year ago, and she said she more or less had retired. Though she was thinking of getting back to work. If you don't stumble into her at the May Bonsai Show at the Chicago Botanic Garden, check at Hidden Gardens for her pots.