You need to go to the bank the same day you go to immigration, have them update your bank book, have them give you a letter that shows your balance and activity on that day and provide you documentation that proves the money came in from overseas... so 3 things.
Plus you'll need whatever documentation you need for the non-o in the first place.
well if you are retired or married to a Thai citizen then that would be the proper visa type for you. If you are neither of those but want to live in the Kingdom full time, the LTR, elite, non-B, and non-E are all options.
Obtaining the correct visa for your purpose in the Kingdom is always the best advice.
There are services you can use that will let you purchase a plane ticket and then a couple days later they cancel it. It costs you a small service fee, but it provides you with the necessary booking.