It used to be possible (and quite easy) to get a one-year non-B, but I do not think it is possible any longer.
Not sure what you are asking for. You probably want a one-year extension, as a non-O visa will give you only 90 days. Marriage non-O are known to be a bit of a pain (and of course you need to be married to a Thai citizen). Retirement non-O are much easier, but you would need to be 50 years old at least. Another option is a guardian non-O, but you would need to have a child and pay the tuition fees.
It's not a letter that you're supposed to draft following a template. It's an official document. For the company profile part, there's no official template, but you can ask a language model to write it for you.