I suggest if you see something they don't carry, ask them to carry it. I've been amazed how flexible the Hy-Vee I shop at has been in getting some stuff in. Sometimes they make me buy a case if they can't fit it in, but sometimes they put the product on the shelf if it's something they think other people will like.
So I guess my answer is find a store that is near you that has a decent section and ask them to special order stuff. A store that has a specific health foods section will probably be more willing to do that for you.
"I used to hate dogs 'til I saw one kill a kid." W.C. Fields