I think you might be over worrying and it is pretty much a standard thin noodle, and I think you could choose any thin noodle that is thinner than spaghetti. If you google lockshen this sounds like it. Also thin wonton noodle. Also shop for a fine soup egg noodle. One variety of thin noodles is called 全蛋麵 (Cantonese jyutping). The noodle is basically just assuming the carb role of absorbing flavour from the test of the dish.

Good luck.