Nobody can give you advice on how to parent and I certainly won't try, but it makes me a little sad to hear that not having a school completely set up would be a deal breaker.
My opinion is that your kids will be just fine, no matter what school near Wokingham they go to. Every school is going to be a good school, and middle class enough that your kids will be fine. Certainly for a year or so. The experience of living in a different country, the history they will see first hand and experiencing an alternative to American society will serve them well their whole lives. That's priceless. I might say differently if you were moving to Edinburgh or somewhere with real deprivation, but Wokingham is middle to upper class suburbia. Reading, on the other hand is full of Junkies