@Marco **********
if you’re planning to marry soon then its possibly best to get the TR. that will give you 90 days (60+30). If married within that time then you apply for a Non O visa in country (2,000 baht). Then when that’s winding down you apply for the year extension of stay. You need at least 400k Thai baht in a bank on your name only. For the initial Non O there is no need for seasoning the money, but for the year extension of stay it would need to be in the bank for 2 months prior. Many offices will require that amount to stay in the bank during the 30 days “under consideration” period. Once you have the year extension you can spend all of it, but it would have to be back up to 400k two months prior to your next application.