The easiest by a long shot is to a reputable agent. This also allows you to keep the 800k baht in Canada at about 5% annually. Which is 40k baht, more than enough to pay for the agent.
If you can prove over 65k baht monthly income, get the affadavit from Canadian embassy.!
If you have over $80k USD, annual income, get the LTR visa. It’s definitely the best visa out there now.
*********************