There's literally dozens upon dozens. And the pay and benefits at county services are usually FAR better than the privates. If there's no service that meets your "gotta have" list, think about moving.
Look for an area where you want to live and then research the surrounding services.
For example, If you say, "I'd like to live in Florida and work for a third service, where should I apply?" You'll get some answers from the FLA peeps. It's also MUCH easier to get hired as medic.
Delaware met all the points on my list, so I packed up and moved from the PNW. Even though I'm no longer working there, Sussex is still the best ALS only county service I found.