Ed visas are now going to require actual attendance to classes. Immigration are turning up randomly at schools on days you are supposed to be studying and checking , they also ask for a progress report from the school . You also have to report and renew your visa every 3 months at immigration
You can only get a METV when in your country of permanent residence as you are in the UK I would expect you will need the money in your UK account. They will wonder why does a UK resident arriving in Thailand as a tourist have a Thai bank account