Hiya shrimp would be just fine!
You can buy the unsalted and non seasoned kind from you you local food store and just put the shrimp in a bowl of hot water and wait till it softens and not frozen anymore and cut or smoosh the shrimp into bite size pieces!! That should do them good! and like you said excellent source of protien
They also sell baby shrimp at you local fish store aswell.....They are pretty easy to find here and the only thing you need to do is soak them....Since there dried and are in a bottle..So that kind is not frozen.
Either way you choose. Its all good! B)
A good brand of baby shrimp that you can find in you lf's is
Tetra Baby Shrimp Sun dried treat