Tube vs solid state (with all apologies)

Unfortunately you have already complicated things by choosing speakers that severely limit amplifier choices. There are a great many excellent sounding speakers that are so easy to drive you can do fine with as little as 20 watts. Mine have no problem with 106dB at the sweet spot with my 20W amp pumping out bass dynamics and detail you simply must hear to believe.      

A little knowledge goes a long way. The range of components that are out there is incredible. The combinations are near infinite. If only we had infinite funds and time we could afford to go at it like you are. Being short on both I restrict my choices to things I know will work well without foreclosing on other good options. Like your speakers have foreclosed on the option of running a superb 20W tube amp that you could buy for far less than what you will spend on preamp, amps, etc trying to bi-amp ML. Better sound for less. Or a science project. Your system, your call.   

There is an excellent book, The Complete Guide to High End Audio by Robert Harley. There's some guys here, not just me, extremely adept at wringing the most from their audio dollar. There's also guys with a knack for spending, complicating, running in circles. Happy to tell you what you want to hear, not so good at what you need to know. Time well spent figuring out which is which and who is who.  

the Martin Logan choice wasn’t arbitrary. I’ve known one of the founders for many years having lived in Lawrence, Kansas most of my adult life. I had the chance to do a service swap, but at the time needed to pay bills, feed kids, etc. I’ve been listening to them however for the better part of thirty years. My bias… I own that. 
I’ll check out the book! 

In guitars vacuum tube amp,in Audio personally 
Solid state has much similarities , Mosfets , Jfets, bipolar transistors come pretty close in sonics in a good quality solid state amps ,and more current ,control for drivers 
and sounds very good , if you want a bit of bloom or perhaps a bit bigger soundstage a vacuum tube preamp. To add to it. 
I have owned many tube amps ,and just tired of tubes to replace ,or blowout unexpected and taking out a channel ,
if you don’t mind then enjoy ,myself as I get older over 60
i want things a bit easier .

Good manufacturers can and do get the most out of either, tube or s.s. amplifiers. The signatures of each are much closer to each other than they have ever been. A bigger consideration is heat, both in the room and on your rack.

Yes, manufacturers of ss and tube have been converging on more accurate sound for decades. Both have improved significantly decade after decade;  You could generalize that solid state tends to provide greater detail and tube tends to provide a more musical experience at any investment level. The greater the investment the better the sound.

That said, over the last 50 years as I upgraded and made my personal assault at the highest end system of greatest sound quality, one by one each piece of equipment has ended up being tubed. By far my current system is the best and most satisfying… all tubed, except the streamer (which is battery powered).