I enjoy living in Thailand now, but my thoughts and conditions may change over that long of time period. So I decided on the 5 year option. The 20 year option is much better cost wise.
I went with the 5 year / 500,000 baht plan. I went to their office in Bangkok to apply so I could ask questions.
You fill out the application wait a few weeks for a background check, then get an approval letter with instructions on how to make the payment, then you get a welcome letter after they verify payment.