Kibble recs for Pancreatitis

Hi all! My 5 yr old Australian labradoodle (24 lbs) was diagnosed yesterday with pancreatitis.

I’ve gotten a lot of recs from the vet on some dog food suggestions to switch our dog(s) to: Royal Canin, Purina Pro Plan, Science Diet and Iam’s. We have two doodles and are looking to switch both to the same food to keep them consistent. As some may know, these prescribed GI safe foods like RC and science diet come in smaller bags and are very expensive. Does anyone know which Iam’s is “the” recommended Iam’s? Or is there a recommended crude fat percentage the food should be under? Looking for dry kibble only at this time, preferably one that won’t break the bank. Thanks!