@Steve *********
so you plan on retiring here, which is all well and good
BUT
my question would be how much time in country have you actually spent at one time. Living here surrounded by these people <- that would be the thaiz
****
ain't the same as comin' here as a tourist knowing you're gonna leave in xxx days. :O
I'd say get a single entry tourist visa from a thai consulate in your country BEFORE you wing your way here. That will stamp you in for 60 days, and you can extend it based on marriage to a thai for another 60 days AND some offices will even let you extend it for another 30 days on top of that (the normal 30 day extension).
That would give you almost 5 months in country to decide if you can handle it or not.
If after that time you decide you do wanna stay you can easily get a 90 day Non-O visa based on marriage at a nearby thai consulate, then apply for a yearly extension of stay (also based on marriage at your immigration office)
Good Luck in your endeavor. :)