What is the best visa option for a 54-year-old planning to retire in Thailand?

Don't let your dick think, let your brain do the work!

It appears that your only other alternative is to get a 60 Tourist Visa from London Embassy online turnaround is approx 5 days although they do recommend allowing 15 days

Once you are here in Thailand get in touch with a Visa Agent straight away thery are everywhere in BKK and Pattaya, they will open a bank account for you and discuss other options for a 1 year visa this service costs around 30k baht (You do not need to have the 800k money in a bank account) this method is not the correct procedure but a lot of people use it.

Other than that you will after wait until your legally married to a Thai and that will open other options up for you like a 1 year marriage visa ( 800k baht not required)obtained at Savanakhet Laos which means you leave the country every 90 days and return totally legal and legitimate

come in on visa exempt or tourist visa< get married

put 400,000 in the bank

convert to90 day non O an than 1 year extension

Get married first.

The only 1 year retirement visa you can get from an embassy is the non-OA visa. This is a 1 year multiple entry visa that requires you to show 800,000 in funds provide a criminal history check and medical exam form, and show proof of $100,000 in insurance for 1 year.

Or you can purchase a non-O visa which will give you 90 days in Thailand and once you arrive you can get a bank account setup and 800,000 moved over into the bank account and then apply for the 1 year extension.

Or you can go as a tourist and then get a bank account opened and setup and move the 800,000 over and apply for the non-O 90 day visa in Thailand, followed by the 1 year extension.