Hi American here. Wife is Thai and German. I used Ho Chi Minh evisa. I applied last week on Monday for my Non Imm O single entry and got the approved visa back on yesterday (Sunday) just remember that the proof of residence they are looking for is a picture of the Vietnam entry stamp in your passport. I didnt send that in at first if I did then it would have been approved on Thursday lol.
I had been visiting for a while so I had a lot of the stuff before we did the visa. Bank account? The seasoned 400,000 and the marriage was already recognized in Thailand too.