so go retirement visa, renew year by year, Enter visa waiver , apply within country, there an agent do a visa run for less than $200 plus cost of visa.
No need to leave the country.
And when you have 800k THB balance in the bank, you don't need the SSA statement.
Assuming you have US passport, just buy tickets, fly, go to immigration, ask for a letter of permission to open bank account, state your intention to apply for retirement visa. Then go to Bangkok Bank, open account, deposit 800k thb minimum.
I recommend after open account, get an agent to help you file for the visa( knowing someone in the immigration help speed thing up.)an agent can cost you around 5-8k thb.
If you know how, not hard at all. You don't need to go back or apply in US.
Just arrive with 60 days visa waiver.
Get an agent to help, it should be done within 45 days. Any idea which city to stay?
I stay in Huahin, I am Thai, so I don't need any visa, however my sister is not, so she has this agent run it for her.. this agent very honest and know her ways around. Plus Huahin is a small town with Immigration office, so westerners that Retire here has some degree of easy immigrants service.