Hmmm...I would just look for a bag of "Ikan Bilis" from Malaysia. Yes, a Thai store would be likely to have the same thing, probably in a Thai version, and there's nothing wrong with that. As long as they're dried and salted, they should be fine. Some Chinese stores have them, especially big ones like the Hong Kong Supermarket outlets in New York, which make sure to carry products from all Southeast Asian countries and to all Southeast Asian tastes. My perception is that the proportion of ethnic Chinese people in New York who come from Malaysia, Indonesia, and Vietnam has increased tremendously in the last decade, and I suspect the same is true in various other parts of the U.S. and Canada.