You really have to do a lot of research not only by the state alone but also the town , and school system you are looking to move into. On top of all of that you have to also look for medical care as well as service providers.

I can tell you that my wife and I did six months of research before moving. You first find the state then the schools and medical care, and then from there look for the towns close to those areas.

Boy howdy! Found that out the hard way when we moved to MT soon after DS was diagnosed! They put us through the ringer & made me feel like a leech when I asked for services/SSI! PA offered all that we did not seek it out ourselves & when we got here all that went away & we were left out in the cold. Sink or swim here.

The first thing is to not move to a state that has no state tax because than means less revenue so less services. Second the north is far better than the south. The best states for ASD are NJ and MA, but some other northern states like NY and Wisconsin are also not bad. NJ has Eden and MA has New England Center for Children, they are both good although I like NECC better, we used Eden in Florida because they have a location there but the rest of the state services are horrible.

I lived in FL for 4 horrible years and had to leave after spending thousands of dollars out of pocket. then the fact that the medical care is horrible and we had to travel 3 hrs for a good doctor just made things worse.

I live in MA now about 20 mins from NECC where my daughter goes and the school district pays 360k a year for her services. My son who is also ASD is in public school and gets all his services at school but that is all he needs. He does get pulled out of class to be in his special Ed class but goes back into the standard class if they think he would like or benighted from it.

We get SSI for both children and they are also not on my insurance, they get Mass Health which is put state insurance. So between the two we have no co pays and no RX costs either. My daughter gets pull ups and vitamin drinks paid for by Mass Health as well. I do not have to tell you how good the medical care is here it is nationally known. Children's Hospital and the Laurie center which are both great.

The one thing I will say is that you are better off even in this state it is better to be in a smaller town than a bigger one or city just because there are less children and even less with issues like ours so you get more attention.

To me better services and care start with having state laws that force insurance carriers to provide for treatments. Usually it follows that there are fewer and reduced services when the business owners are left to deal with payment for services on their own.
See the following link for current states with health care reform laws.
http://www.autismspeaks.org/advocacy/states
MN fortunately had some great educational services before insurance coverage reform was mandated, I don't really know about other states but this is where and how I would start to search for a new place to live. Good luck I would think that education achievement rankings would be a good indicator too.