If money is no object, then consider Westhill surrounding villages, or Banchory (or surrounding villages) These are the areas which have the best high schools which means their cluster primary schools are probably pretty good. Banchory and Westhill are the most expensive of the areas on your list. Alford/Kemnay are the cheapest. IMO they aren’t particularly good places to live (but I’m sure someone will be along to tell me how perfectly lovely they are!) They are far more remote too. You could go further West from Banchory and consider the villages towards Aboyne. Torphins, Lumphanan (not Kincardine O’Neil it’s tiny!) Aboyne Academy is quite good too, and the village is lovely too.
It will depend on the level of additional support your child needs. If they will be in mainstream with additional support, all schools provide this, but if they need to be in enhanced provision, you would need to contact Aberdeenshire council to find which schools have a unit within the school.
Co-ordinated support plans (CSP) are not easy to get as the criteria is pretty strict. They are for children with complex or multiple disabilities which need a high level of support from the school / local authority, or from an outside agency. My daughter has ASD and cerebral palsy but even her level of disability was not considered to qualify for a CSP. Most local Authorities avoid them as far as they can.
What you will have instead is an Individualised Education Plan (IEP). This is actually a more useful document. It has to be updated every year and this is triggered by a Team Around the Child (TAC) meeting. It can actually address more than the CSP as it focuses on the whole picture rather than just what each agency is involved in.
The North East of Scotland is lovely, I have very fond memories of growing up there and would love to relocate. Good luck!