Try the bank where your savings are. I have a friend on SSI disability who took out a mortgage for a first home, so I know your income stream is acceptable.
Borrowing is usually a bad idea. You have to pay the money back with interest, and on a fixed income that is difficult unless the loan is for something that cuts your long term expenses (like my friend's mortgage versus paying rent).
When you get to the part of the forms that asks about employment, just write 'retired'. Skip any questions you don't have an honest answer for. They (loan originators) are not concerned about employment, they are concerned about your ability to repay them.
Why do you need the loan, may I ask?
