I highly recommend Thai Visa Centre. I used them for my Non-O retirement visa with multiple-entry, and they handled the entire process from beginning to end.
They picked me up, had representatives accompany me, helped me set up my Thai bank account, and took me to the Bangkok Immigration Office. That is where I really understood the value of their service.
Bangkok Immigration is huge, busy, and can be very confusing if you don't know exactly what you're doing. I watched so many Westerners walking around looking lost and frustrated, trying to figure out where to go, what paperwork they needed, and what came next. My experience was completely different. I had a Thai Visa Centre representative with me throughout the entire process. They knew exactly where to take me, what needed to be done next, and helped communicate with the immigration officers. I knew exactly where I was in the process 100% of the time.
The process still took most of the day, but it was relaxed and organized. I honestly believe it could have taken me two or three days—and a lot of frustration—if I had tried to figure everything out myself.
Their assistance with opening the bank account was also extremely valuable. Even something that sounds simple can become complicated when you don't speak Thai, and having someone there who knows the process and can translate makes an enormous difference.
Thai Visa Centre also handled my first 90-day report, and once again, everything went smoothly with no issues.
Their service is not cheap, but there is a big difference between something being inexpensive and something being a good value. For what they provide, I believe Thai Visa Centre is an excellent value. Don't pick up pennies while walking over dollars. The time, frustration, uncertainty, transportation, translation, and potential mistakes they saved me were well worth the cost.
If you're considering a retirement visa in Thailand and want the process handled professionally from beginning to end, I highly recommend Thai Visa Centre.