Welcome to EpicSki, Edseas2. I'm not aware of any pmts-affiliated ski schools in New England. In fact, their website lists only two small affiliated schools anywhere--one in Wisconsin and one in Colorado. I think their site also lists a few instructors trained in pmts, and the resorts where you can find them--don't know if any are in your area. If you really want an "official" pmts lesson, you may need to inquire about one of the camps they put together somewhere. Otherwise just tell the supervisor at any local ski school exactly what you're interested in, and (despite the pmts people's protestations to the contrary), you should find a good instructor who can deliver. You've read the books. You know what you want. If you don't get it, go back and get your money back!
If you listen to the pmts people, they'll try to convince you that what they offer is unique and superior to what you'll find elsewhere. I promise you that you can find good and knowledgeable instructors everywhere who are well-versed in the same concepts, and who can guide your skiing anywhere you want it to go, to whatever extent you are prepared to take it.
You can also find incompetent instructors everywhere, so be picky! Ask for a certified instructor, and tell the desk you will ask for your money back if you don't get what you pay for. If you like, ask if they have someone on the staff who is particularly familiar with pmts. Don't be surprised if you draw a blank on that, but don't be disappointed either. When you find a good instructor, explain your understanding of pmts, why you like it, and exactly what you hope to accomplish, and believe me--the instructor will understand and be able to take it from there.
Despite marketing-motivated claims to the contrary, it's really all about skiing, and great skiing is universal. All great pros make it a lifetime professional pursuit to learn all they can about the sport, from every possible source. They all look at the same great skiers and world-class competitors and derive their technical foundation from diligent analysis of what the world's best are doing. The very, very best pros do this without prejudice, with an open mind, and without the restriction of dogmatic attachment to any particular set of beliefs. They are flexible, thorough, and grounded on a solid understanding of skiing movements and techniques, and they are able to tie effective techniques to any outcome you desire. And they may be affiliated with pmts, or any national or international instructor association. Or not. (Unfortunately, there are also incompetent instructors affiliated with all instructor associations.)
So--the key to getting a great lesson, besides finding a great instructor, is to be clear on what you want. Is it really pmts, a particular technique, or a particular progression, or is it skiing? What I mean by that is that you should be clear on what it is you love about skiing--what are your goals, both short and long-term? What is it about pmts that turns you on? Is it really pmts itself, or is it some outcome, some new capability you want to master, some sensation or thrill you seek, that you believe pmts will deliver? Is it "parallel"? (And if so, what is it, really, about "parallel" that intrigues and entices you?) Carved turns? "Control"? Win a NASTAR medal? Master powder skiing, steeps, ice, or bumps? Impress your friends, and strangers from the chairlift? The thrill of speed? Once you know what you want to accomplish, tell your instructor, and you'll be amazed what you can accomplish. The best instructors, regardless of their affiliation, will create a dogma-free learning experience tailored just for you.
Whether you believe that the techniques you'd learn in a pmts lesson are unique or not (you know where I stand, but you need not take my word--or anyone else's--on that), I submit that no technique stands alone as an end in itself. Is it really the technique that you're looking for, or is it something that you believe that technique might do for you that truly inspires you? Technique should serve your interests--not the other way around--don't you think? So what interests you? And if you say "good technique," you are not alone. But I'll repeat--there is no such thing as "good technique" in itself, no such thing as "good technique" until you tie it to an outcome. When you do, all great instructors can teach it!
Alpine World Cup racers, mogul competitors, big mountain free-skiers--they all apply the full gamut of techniques, even within a single run, depending on their intent and the outcome they seek at any given moment. My advice, which you are surely free to ignore, is to avoid dogmatic attachment to any specific technique, and instead to develop the broad spectrum of skills that will take you anywhere you want to go, and that will let you apply any technique, any time, as you like or as you need.