Firstly, welcome to Doha, and I hope that you and your family enjoy living here.
I would urge you not to overlook the new Newton British School. It opened last year in al Waab, and so far, I have been quite pleased with it. The class sizes are small, staff and teachers are very friendly, and they follow the British Curriculum. You may wish to ask other parents about it as well, just to get a complete picture, but again, I would encourage you to consider it seriously.
Good luck!