The one thing you really have to research and make sure about is coverage outside your 'home' area.
Many insurance policies are tied to a specific area, set of providers. If you will be traveling across the country - you might not be able to find insurance in your area that will give you the ability to go to doctors no matter where you are located.
Some of the more popular residence states, Texas & Florida, have many insurance companies which offer policies with nationwide coverage.
Investigate the details.
If you explain your needs to an independent insurance agent, they will try their best to find you a policy that meets your needs. Otherwise they won't get a commission and get paid.