I believe the marriage visa linked to type O is good. You only have to show
*****
0 baht in Thai bank account, plus currently no health insurance is required. The type OA visa is considerably more demaanding
*****
0baht deposit in a Thai bank account plus an acceptable health insurance. The deposit in Thai bank account can be combined with an annual income to attain the requirement. The Thai marriage visa also allows the possibility for you to work .