Hi and welcome to YT....I'm not sure which kind of diet would be best for him since he had a bout with pancreatitus..(ms) But there are many others that have dealt with this issue...so I'm sure they'll have some great advice for you!!
Vets push people to purchase science diet simply because Hills pays them to do it! Not because it is healthy for our babies!!!
So getting your little one off Ceasars and SD is a good decision!
I'm thinking that more meat based and grain free dog foods might be better for him....but I'll let others tell you for sure!