I brought the woman who is my wife to the US. We took time building an in person relationship over 5 years as I traveled back and forth. We then had a traditional Thai Buddhist marriage, but did not register marriage in Thailand. This was followed three months later by our US marriage. To get her to the US I hired a US born atty living in BKK and applied for a fiance visa. Took about a year to get done I chose the fiance visa because I wanted her to have a three months in the US to decide if she wanted to stay before having a formal US wedding and working to change her over to a marriage visa and get her a green card. We are now married over 10 years, of course with ups and downs due to cultural differences. I should also say she was about fifty and I was 55 when we met.
There are many sites on the internet that look at these variables at various monthly budget figures. Suggest you do some research there to get answers that will best match your individual budget and personal priorities.
I just went through getting a marriage visa through the online portal. I have a state pension from Oregon. All I had to do was go to my portal on the state pension website and they had a statement much like my bank statement indicating what payments they have made and when. It was available for download as a pdf. So you might check to see if your state pension office has such a portal.
Change $100 at a money exchange. The Super Rich money exchange usually has better exchange rates. You can find out the nearest location on Google when you get there. Just use Google translate which is in Chrome, to change the page to English. Make sure you take only new $100 bills, the kind with the ID strip and hologram. Keep them new and flat (they love no creases, bent corners or small tears) for the best exchange rate. Second best, but with some fees attached, is to use an ATM at a bank in one of the zillions of malls or Tesla Lotus market places.