We are moving to the charlotte area at the end of this month. We looked into schools all over. Charlotte, despite it's huge size does seem to have plenty of good schools (many BAD as well...look carefully)
There is a good website, but there is a fee for full access, but I used it (happened to use it 2x as we moved last summer and are moving again!) and it was very helpful.
PSK12 Public School Rankings
It will rank schools in a county by test scores, and when you click on the name of the school it give more detailed information, breakdowns, I think (subscription expired last week) of test scores, and demographic information, which should help if you're looking for diversity. There are many schools that are very skewed and not very diverse, so you could stay away from the less balanced ones.
Then you can take the schools you like and search properties BY SCHOOL and within your price range parameters here: (if the links get cut PM me and I'll pm them back)
Charlotte NC Homes For Sale, Houses for sale, houses, real estate, for sale - helenadamsrealty.com
I'm not a realtor, and dont' work for these folks, but they were immensely helpful when I searched for our new home.