Looking for schools in Bangkok

I currently live in New York, but I am relocating to Bangkok later this year. My wife and 8 year old daughter live in Kalasin, where she attends St. Joseph's Catholic School. I am trying to learn as much as I can about primary education in Bangkok in order to provide the best possible education for our daughter. I am not coming on an expat package, so the International School Tuition places them out of our budget (if not for expat packages, they would be out of most people's budgets).

Is there a private school system that comports with a Thai education (similar to what she has now) and what is the typical tuition? Further, what other "good to know" items are there (e.g., "tea money"). I'm ultimately not worried about her English language education (I'll either take a direct role in that or Ill hire a tutor), but I am concerned that she receive a quality primary and secondary education that goes beyond rote recital.

Thank you in advance for any assistance you can provide.