Can I apply for a Type O retirement visa in Thailand using a combination of 800K baht or 65K monthly income?

The rule is clear, you can use either all banked money, or monthly income (and if your embassy doesn't issue the income affidavits you need to transfer in to a thai bank account in your name only a minimum of 65K baht each month every month.

Now it's totally up to the immigration office as far as how many months they will accept when you first apply for the in country 90 day Non-O visa based on retirement. MOST want to see at least 3 months (some want 6) so that's why I said GO to your immigration office and see what they want. Also remember if you're using the 800K baht banked money it has to come from abroad (can't be a domestic transfer or a cash deposit into your account) ..

my dad showed his 65k pension from day one... if that helps. best i think would be if you get a thai person to call your local immigration office and ask.

I think you're going to have to post on a f/b page related to where you live in thailand and ask what that office is doing.

AND I'd say get to your immgiration office and get the hand out listing the requirements to do a conversion from amnesty to a Non-O quickly because most offices have an "under consideration period" that the application goes under (usually 14 days) meaning you need at least 15 days left on amnesty to even apply. That means if you don't apply by the 11th (this friday) you're not gonna be able to even if you do meet the requirements.