I am a Canadian who gets 3 Canadian Pensions totaling around 70,000 baht a year. This is all deposited into my Canadian bank account. I was told to: (1) get letters from my Pension plans stating the amounts; (2).send these letters with an affidavit signed by a lawyer by email to the Canadian Embassy in Bangkok; (3).apply to Thai Immigration for Retirement Visa based on 65,000 baht per month with copy of the Canadian Embassy confirmation of 65K baht per month income. I am in the middle of doing this now and waiting for the Canadian Pension letters.
US $ is what you get in cash machines. Lots of these machines around. Use Kip only for small things. Outside Cambodia nobody wants it. Don't get stuck with a lot if Kip.