I ditto going grain-free, as that seems to cause problems for many dogs. Some suggestions for different protein sources could be duck/fish-based/kangeroo/venison.
THis website
www.onlynaturalpet.com seems to have a selection of good quality grain free and fish based foods and shipping is free over $75. I've ordered my dog's Addiction raw dehydrated from there before and got 10% off as well.