God bless you, Sandra and Nigel, and other parents like you!
I understand quite well, through what are you going now, but, believe, the love and patience, you're putting into your kids, will turn them into happy and successful people very soon.
Make them move and learn what they have to learn- that's really is the main key to the success. Well, sometimes you can lose your energy during it, but your kids certainly will be the winners.
(In each class i teach, there are about 3 ADHD kids and 60% nervous or very active ones, so we jump, crawl and so on, and so on... Ohh, poor, poor, poor couple of calm and peaceful kids. Sometimes they look into my eyes sadly and there's only one question into their big eyes, "Teach, can we sit still at least one lesson? Please..." Then we play "Peace game" and i'm so happy to watch, how my grasshoppers are able to be still longer and longer.)
To be honest, i don't trust experimental schools (seems such is Steiner school, Sandra had mentioned).
We had Montesori school here. OK, they had a lot of fantastic things, but, in my opinion, their idea, "Children will learn, when they will be ready to. Simply trust their feelings." didn't work. For example, they could crochet during English lesson. Year by year, and my little neighbour, who was a student at that school, became as an excellent crocheter, but couldn't say any word into English and had to look for and pay for a private teacher...
And one more time allow me to say, "God, bless you, Sandra and Nigel", cos i know, what happen with the ADHD kids, whose parents don't care and use to say to the teachers, "Your student- your problems."