Pilates, Alexander Technique, Yoga, etc. can all be quite helpful. PT sessions can be good, but you must treat PT as a partnership/participatory activity instead of something done to you. I'm sure Bob Anderson's book is good, and I like Pete Egoscue's "Pain Free" books.
You did nail one thing: the critical step is awareness. Moshe Feldenkrais figured this out about 50 years ago; he developed Awareness Through Movement lessons. I love the Feldenkrais ATM classes: each hour-long session plays like a little science project.
I'm also quite fond of Eric Franklin's work and books. Franklin has created some of the best exercises plus imagery anywhere to restore our bodies to a state of fluidity/grace/pain-free. There is a huge linguistic component to healthy posture and movement; Franklin has done the best of modern instructors to address the language. linguistic component of body/mind work. @FranklinMethod puts out some great tweets on this topic: follow him.
What's the right one? It depends. If you had a friend who you trusted who was an instructor of Body/Mind discipline XYZ, I would recommend doing that. The most important thing is what you bring to the table -- what you're willing to commit to do. And there's no rule you have to do only one body/mind discipline. Find what you love to do, and do it.
Structural Integration is a fantastic thing to do, but it's a serious investment and you shouldn't commit to the 10-session (some schools are 12-session) series unless you're ready. I really like SI, and I really like the individuals who have become SI practitioners. They seem to march to a different drummer than most body/mind workers.
Thomas Myers, who has his own SI school, wrote the fantastic essay "Spatial Medicine" (available <a href=http://www.anatomytrains.com/explore/spatialmedicine/expanded>here</a>. In that essay, he describes a way of thinking about our health and what role "spatial medicine" plays in it. Some body/mind workers speak in a very "woo woo" fashion, but Myers speaks in a way that everyone -- including the geeks and engineers -- can understand and enjoy.
The poster "Dead Ernest" was dead right: no widget will fix what ails you. What will address your concerns is a comprehensive whole-system approach to your posture and movement: a new mindfulness to bring to your posture and movement. It's not a thing; it's a way to approach everything.
Finally, check out the essay <a href=http://marvinsolit.site.aplus.net/pgs/health/great_unwinding.htm>The Great Unwinding</a> by the late Dr. Marvin Solit. I don't agree with everything he says, but many of his words are tremendously satisfying to me. Marvin was a mathematician, an inventor of many cool toys and puzzles, and a body-mind worker. I consider myself quite lucky to have met him before he passed away.
I apologize for the large answer. You have asked a vast question. It looks like a simple question, but it is not. Nature builds in whole systems; profound changes to whole systems must themselves be systematic.