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
You get a Evisa which you print out and show to immigration each time you enter. You get 60days on entry each time. In order to get the multi entry visa you must show you need it. You will also be asked to show your first entry date first exit date AND second entry by means of an actual ticket