So you had 1-year visas for 4 years in a row now?
Then why don't you go ahead apply for a permanent residence?
To do that you must have had 1-year Non-immigrant B visas for 3 years in a row and be able to speak a minimum of Thai, which you should have learned in these 4 years
They will test your Thai though.
Trond,
http://www.affiliateguiding.com/