Ellie May, thank you very much for the prompt reply
Unfortunately we only have one kind of Science Diet here

Puppy and adults small bites.
I have been going round this forum a little more though, and so far I've concluded that the best foods are:
1.Innova
2.Canidae
3.Royal Canin
I'm not sure about Innova and Canidae, but I did see Royal Canin for Yorkies on the last pet store I visited. I remember it was for the adults though.