Bilingual And Thai Private And Public Schools In Bangkok

I'm a student of Master of Educt'l Program and i started working on my Thesis Proposal. I am interested to conduct the study to selected Private and Public schools in Bangkok, particularly Bilingual schools and Pure Thai schools (i mean Pure Thai, those school using only Thai language as the medium of instruction) of both private and public.

However, I'm not sure if the public schools in Bangkok have the Bilingual Program. I heard that public schools offering the English Program but I can not equate this to Bilingual because they have different curriculum.

Another thing, are there still schools (both private and public) considered as Pure Thai Schools??

Please if you have information about this matter, kindly response!! Thanks