You can check with these companies,
blue cross blue shield and
Humana, but the the best way is to go to a local, independent agent. They have a real office if you have a problem, they're familiar with your local marketplace, and know who is most competitive; and they know which companies don't have very many providers in your area.
I'm sure you'll get offers for "health discount plans" from this question. They are usually a bad deal, and most people end up hating them, because despite what's claimed, MOST providers won't take them.