I've been looking around. My daughter is almost 3, so she'll start next year. However, I'm not a rich farang, I have a job here in the scuba diving business, and the private schools are real expensive.
Dulwich is the biggie. Then you have Montessori, and the other expensive one is QSI. Not a lot of difference in price between the 3, all super peng. We have been looking at
Kajonkiet school, which has bilingual teaching and foreign teachers, looks pretty good and much cheaper.
I found
this page comparing schools on the internet from Phuket Magazine.