Lexicon LX-7 or Bryston 4BSST's and a 6BSST???

Lexicon and Bryston at one time were the exact same thing. Just a different face place and silk screening on the rear. That has not been the case for several years now.

Lexicon is part of Harman Group which also owns Crown. Crown amplifiers makes the amps for Lexicon. Lexicon does not make their own amps and when they were being developed they were voiced against the ST series of bryston.

I would reccommend the SST series from bryston over the lexicon. It is more cost effective and comes with the 20 year warranty in addition to the fact that its technologically speaking more advanced than the LX7 and Lx5.

I've sold/dealt in the Lexicon/Bryston line(same stuff basically, from the same manufacture). I think either way you'll get similar results honestly. If thats' the way you're going. considering the sonic abilities of the M&K speakers, and the processor, you'll do fine with whatever amp you chose there.