btw, the embassy asked if i wanted an official certification of my passport for an addl $50. They said some districts require it. I rolled the dice with my regular passport. Our district never even asked about it.
Not sure if the same but i just did mine at the US embassy. The longest part was getting the appointment for them to take 5 mins to notarize my signature. The Canadian Embassy may be more service friendly. Then you have to have a translation service provide a certified translation. They will also go to the Thai MFA and get the required MFA certification. That takes about 3-4 days to get that paperwork. Then you are all set to go get your Thai marriage license at any district office. I just went through it. Good luck!