I know how busy and stressed you are due to work and driving time, and am glad that you will look for the best school and private teacher. I do not want you to worry about costs at all. The important consideration is the quality of the teaching. Your convenience is also important. You do not want to be stressed out going to an inconvenient school.
Pronunciation is extremely important. That is why I recommend a teacher from England. In addition to normal ways of looking for a private teacher, you may try contacting the British Embassy or Consulate and the English Church (Church of England) for recommendations. The pastor of the church may know some one good. It is important to get a woman teacher.
Please tell the teacher that you do not want to rush through a book. You want to be drilled and drilled to get pronunciation and grammar perfect.
Please go to the schools the best families in Thailand would send their children or the top companies in Thailand would send their top officers. You are the best and your future is important.
When you need funds, please provide me with the following information so that I can wire it to your bank:
The name of your bank.
The Swift Code of your bank.
The address of your bank.
Your name.
Your account number.
Your address.
Any other information that your bank may need.
Good luck and all the best.