This recipe uses both fresh cooked shrimp and dried shrimp. Dried shrimp are available in Asian grocery stores, look for the larger pink type. The salad will be delicious without the dried shrimp, if you are unable to find them. The nuoc cham will make more than needed for this salad, extra can be used for other salads and slaws.
Fried shallots are available at Asian markets but can easily be made at home. More importantly, the oil from frying shallots is a flavorful addition to any salad.