the embassy in Cambodia or Lao probably will not give you back to back tourist visas. You best best is a border bounce for 30 days and then extend once for 30 more. After that fly to another country for a week and then come back. After you've fill a few pages of you passport with back to back entry stamps they may question you on why. It would be helpful to have a phone number of a Thai girlfriend to let them know why
If going on wife visa, she will need to pass the background test, and embassy interview. It will take you 2 years of, waiting to get her a visa and green card. Your best bet is fiance visa, which will take a year after above checks