A Thai retirement visa is much easier to get, my wife is Thai and the Thai immigration recommends retirement visa, much less paper work. In saying that I entered Thailand on a 0 visa then after my first 90 days I had a option to get either a retirement or marriage visa, remembering your age and bank details are required. Generally they are very helpful, it only took me 2 hours and a little paper work.
They need to see all the information including marriage certificate and birth certificate of your child also your address in Thailand and your personal bank details and or Thailand bank account details.
The more information you give the better. I got rejected the first time for just saying would be out of country for over 3 months. Must have a valid reason.