Get the best you can afford and don't stress too much about it. Going anti-biotic and hormone-free is a good start.
Some of those farms that have grass-fed beef might have or know where to get good chicken. Ask around, farming communities are pretty tightly knit, so they'll often know someone. They might have chickens even, but not enough to sell to everyone, so if you have a relationship you might be able to get some.
Check at a local butcher's place where you get the grass-fed beef.
Are there any Amish communities around? Amish chicken is delicious, the best I've ever had.
Think about raising your own chickens if you've got a yard. Hens give you eggs and don't make noise like a rooster does.