Paula, its nice to meet someone who has transitioned that long ago and I can feel with you to want more done as the time passes. I did transition in the 1990ies and did not dare to do voice surgery at that time because the surgeons seemed to have bad techniques or not enough experiences to produce good results. This seems to have changed now.
I also know those 4 names - Drs Thomas, Kim, Haben and Remarcle. They all have different techniques to a degree. Dr Thomas in Portland has a very invasive surgery that can, if luck and healing are good, create a good voice because it also changes resonance. Dr Kim has a special refined version of the glottoplasty (or "vocal fold shortening" = VFS) technique and he has a lot of experience. Remarcle does glottoplasty, but uses a different technique than Dr Kim (laser instead of microscalpels, dissolving threads instead of permanent ones, he creates more scar tissue at the web than Dr Kim does). Dr Haben does the glottoplasty similar to Remarcle, but adds a trach shave and a CTA to it to maximize the changes. CTA is probably what was offered in the UK in the 1990ies... it has a couple of disadvantages (Dr Kim/Yeson Website lists a comparison of the available methods).
Now since you say you have a good voice already, I would assume you have good resonance and your pitch is not abysmal. So I would not risk Dr Thomas, because your voice is already well enough in terms of resonance. I also would not go for the "triple" of Dr Haben, because that makes mostly sense if your pitch would be very very low. So I would think that glottoplasty would be the best choice for you and for that you have still three options - Remarcle and Haben seem to be similarly good. There is apparently also a Doctor in the UK who does something similar, but I do not know name or reputation. Dr Kim does his modification of the glottopplasty, which I personally favoured after comparing the techniques. The main reason was that the "web" is not really a web but a very clean and tight suture. The new commissure (the V shaped part where the vocal chords meet) is very much V-shaped and scar free with his method, other surgeons (particularly I compared this to surgeons doing glottoplasty in Germany) may create more of a U shape and sometimes scar tissue is exposed which both causes some hoarseness and loss of volume. Also the complication rate with Dr Kim at Yeson seems to be rather low. There have recently been a few patients of Dr Haben who had complications with sutures and the web not holding. I did not hear something like this from Remarcle yet, but the reports from patients of his are not so numerous.
