WTB Magnepan 2.7s will my amp be sufficient.

You have PLENTY of amplifier.  The 14B SST2 will drive almost any speaker available.  No worries...

Why 2.7s? The last time I saw a pair of 2.7s for audition in a store was 1996.

I could be wrong here, but I’m pretty sure the current 1.7i design is at least the equal of the old 2.7s. and to paraphrase mofimadness, with 900 wpc into 4 ohms, your Bryston won’t even be breaking a sweat.

I power my 1.7s with a Bryston PMF1150B, rated at 100 wpc into 8 ohms, and probably close to 200 into 4 ohms. The speakers are in an open architecture living room--totally open to the hall and dining room with 15’ high cathedral ceiling. The Perreaux drives them louder than I can stand (playing big band and fullscale orchestra) and stays clean all the way.

Your Bryston could probably power a mid-sized town. :)

I have to admit, however, that when I auditioned some 2.7s in 1996, I liked'em better than the 3.5s (or 3.6?) even though the sales rep was pushing the 3.x series as superior.

I have 300 sq ft to fill with sound, so I’m in need of larger speakers. I also dislike the sound of the employment of full range quasi ribbons in the new .7 series. It sounds phasey to me. And the true ribbons don’t sound coherent with the rest of the drivers in the older large models. I’ve auditioned the 3.7s in my home and preferred the sound of my 1.6s except for the better bass extension in the 3 series. 2.7s would be the best of both worlds.