A bank account is easy to obtain but sometimes requires a bit of patience.
Just select the bank where you want to have your account...if they refuse to open one for you because you're not a resident just go back a day later and talk to a different bank agent, or just go to a different branch of the same bank. Just like everything else in Thailand, no two people interpret the rules the same way.
I was turned down twice at Kasikorn Bank years ago - and the third time I walked into the very same branch they opened my account without batting an eye. Typical Thailand!
Years later I opened a second account at Bangkok Bank and they never even asked if I was a resident.
TIT