Success (I hope). After searching online, at gun shows, LGS, and even talking with the importer/manufacturer, I finally found someone who a) carries Golden Tiger .223, b) will sell less than 1000 round cases, and c) actually has the product in stock.
See Golden Tiger .223 56gr 20rds from Ammo & Parts
I placed an order last night and received automated confirmation. We'll see if Monday I get any "bad news" or they tell me the order is on the way.