@Joe ******
well 90 consecutive days is true. For that you'd indeed have to get a tourist visa and then extend. In your case you can go to Laos and back without problem, and then also extend to get 120 days. Exiting again, you can get more. It'll stop at some point and you don't know upfront when that is, but at 60 or 90 days isn't likely, neither is at 120.