Have your US bank, or SS direct deposit into your Thai Bank acct. When 12 months passed, bank will give you letter. And you give copies of bankbook for 12 consecutive months via FTT ( foreign fund transfer. ) after 1st time its easier. I wouldn't park 800k in a virtual 0-1% interest account.
no, just come on over, get visa on arrival, but 2 weeks is about what it takes to get over a 12 hour jet lag, then the cultural adjustment, it's then time to go home.