Keep in mind that you need to be somewhere with good medical care. As a general rule...the South does not have it! I can assure you that LA/MS/AR and probably even TX and FL are not where you want to be! THere is a good doc in Birmingham, AL now, but he is still building his team and I am not sure what kind of support he is getting from the hospital.
Good luck on your Quest!
provides a lot of information on various programs in various States. In many States the special needs insurance is covered under things called waivers. You can contact your target States and see what they offer in their State.
http;//www.familyvoices.org is a nationwide organization that provides support to families struggling with health insurance and medical care issues. Contact them about your target States.
There are lots of environmental issues that you might want to consider including air quality (since pulmonary issues are very important for our children), humidity (which can be just as difficult as cold - I grew up in N Indiana, Chicago so I feel your pain).
Cost of housing and cost of living are biggies too as well as availability of adapted housing.
Get one of those "best places to live" books and then adapt what they say about important aspects of living to what you migh need for a person with a disabiling condition.