please be aware that many (most?) Thai immigration offices require retirees converting a visa exempt or tourist visa to a 3 month Non O have THB 800,000 in the bank and will not accept 12 months of international transfers of THB 65,000 for the conversion.
Immigration wii accept the 12 months of THB 65,000 deposit, but they will not accept for the initial Non O. I use Chaeng Wattana and got caught out by this.