Can anyone give me a few names of good dry foods for dogs with a sensitive stomach?

One of my dogs seems to have lose stools a few times a week so the vet has suggested changing his food to a sensitive one before I start shelling out for expensive tests and such (Does insurance cover these?).

He's currently on Arden Grange puppy food. I have spoken to the fantastically helpfull nutrutional adviser at Arden Grange who recommends their seisitive range, but to be honest at almost £50 a bag, I can't really afford it. I am lothed to change him from AG, but I obviously need to do whats best for my dog.

So if someone could give me a few names of dry foods with decent sensitive ranges I'd be greatly appreciative.

P.S. He's already been on JWB and switched to AG because I couldn't stand the wind any longer. So obviously don't want him back on JWB.