It would be fine to contact the schools and ask to meet the head/SENCO and look around. You have the most opportunity to do this now before your LO arrives. You can tell them you have a child coming to live with you soon who will be starting school in January and you would like to look round and talk to the head/SENCO because the child has some additional needs.
Ask them their understanding of the needs a child who is LAC/adopted from LAC might have. Especially talk about the needs your LO has. Make sure they seem welcoming, and not trying to put you off when they hear your child has extra needs. Ask about their discipline methods, potential problem areas of the curriculum, ask what extra help they can put in place if your child finds x,y,z extremely difficult. Again, make note of thir attitude when discussing this.
The atmosphere of the school should be friendly and warm.
Basically - good attitude, warmth, flexibility, willingness to have a child with special needs in their school and to work with them, any understanding of the needs of LAC/adopted children is great, but if not they need to be willing to learn and to listen to you, friendly atmosphere.
You can consider academics, distance and other things, but IMHO if it were me i would happily sacrifice academics for a school with excellent pastoral care and a great record for helping troubled children. My view is that if your child is not cared for in school then they will get into such a state they can't learn anyway, but if they get the support they need they can make great progress in most schools including ones who do not get good academic results.
I might also talk to any other parents you know whose children go to these schools, and ask about pastoral, and ask about the school dealing with issues like bullying etc. Ask about how the school communicate with parents. Ask about how they deal with 'naughty behaviour' etc. I would also ask whether they think the teacher turnover is low or in their opinion quite high because your child does not need their teacher changing often and supplies coming in and out.