@Chrisze **********
here is the list from the website from Embassy in Vientiane what is needed to apply for a visa, I not see 20.000 Thb on a account in the list: For applicant who wishes to work for an academic institute; as full or part-time teacher, tutor or teaching assistant, documents required are;
1. Official letter from the Ministry of Education of Thailand, or other sub-authorities concerned, approving the employment of foreign academic personnel
2. Recommendation letter from the institution addressed to the Embassy (stating about the employment and visa application) and be accompanied with the certified copy of the endorser's ID
3. Employment contract
4. Form of the Employment Certification
5. Copy of registration certificate of the concerned academic institute
6. Copy of applicant’s academic certificate/record
7. Copy of the recent police clearance or certificate of no criminal conviction.
8. Copy of the previous/current work permit (if any)