Hi L.,
I love that you are so invested in your child's education. Now is a great time as your child is just about to start Kindergarten.
As a public school teacher in FL work works with Special Needs children I hate when people attack an entire states educational system based on their experience. I was educated in the FL public school system and have worked in the system for many years. It may not be the best in the nation but it is full with outstanding teachers, parents, and students.
In response to your question I'm not sure there is a greatest place in the nation to live. There is going to be good and bad everywhere. If you set up a meeting with guidence counselors at the school you are zoned for, you will be able to get a better idea of what they are able to provide for your child. I know that in the county I work there are clusters of schools, each school having a "speciality" in the special needs arena and your child would be bussed to that school at no cost to you, if you "speciality" is not at the school closest to you. Your post was very general so I'm not sure if you chlid would be placed in a "regular" classroom with just teacher services, pull- out services, or in a special needs classroom but look into it do your research and talk to people in your area as well as areas you would look to move to. The people on here that have offered specific schools and places to look into are going to be your best places to start if you are serious about relocating. But you can't discount an entire state based on a reputation. The school by you might be terrible but it could also be the best school and you would miss the opportunity for a great education for your son and spend a lot of money you didn't need to if you don't look into it.
I hope that helps a little. I'm sorry if it seemed a little negative I just hate that my husband and I work our tushies off everyday to provide the best education possible to each individual student we encounter and I read hurtful things on message boards. :)