there are actually loads of little Amphurs within CM you can go to for your kor ror 22. Just go along with your wife and get a few originals because they always ask for them at the immigration when you go for your extension of stay. It usually takes an hour or so getting the kor ror 22 as they have to enter details etc. Good Luck
Ok. Another thing. I usually do my 90 days at the Promenade in Chiang Mai so could I also apply for another yearly extension there? If anyone knows about this. Thanks