There are two styles of pot stickers – Cantonese and Shanghai. I haven’t found any good Shanghai style pot-stickers around here in restaurants, and defintely not frozen ones.
As for Shui Jiao, one brand that is surprisingly good is “Wei Chuan” brand that’s sold in Ranch 99/Lions Market. Tehy sell similar ones in Taiwan also. They have two lines, one cheap and one more expensive. Get the more expensive one . The best flavor I like is the Chives and Shrimp. They use good ingredients, you can see actual shrimp pieces.