I’ll be curious what people suggest. ‘Real’ Thai massage in Thailand’s eyes is certified by The Ministry of Public Health. I don’t believe this is open to foreigners.
The curriculum I’ve seen is a pretty intensive lock in 30 day stay. Open dorm, no air conditioning and directly tied to Buddhism as part of the process.
Based on what you’re said the most prominent would be the non O or non OA visas.
Based on your words you’re married? Each would need their own visa and requirements applied to each person individually.
Long stay using the non O if I read you right you may be financially short. Required deposit into a Thai bank is 800,000 baht, each or transferred income of 65,000 baht each monthly. Converted is $23,000ish and 1,900ish each respectively.