Would like your tube amp recommendation

I’ve got the original MG20s bi-amped with a VTL compact 100 tube mono blocks fed into a Phil Marchand XM44 cross-over which then feeds the midrange/tweeters. A pair of Emotiva XPA-1 mono blocks handles the bass panels. My room is 20x21 but my entertainment system takes up a whole wall and steals 3 feet. I’m here to tell you my 100 watt tube amp(s) will drive the mids/tweeter quite well into the 77db range without any signs of strain. Separation is on par with tube amps in this price range ($2400 pair). I’m not claiming my system is the pinnacle of all sound systems, it’s not. The one I heard at Stereo Design on Clairmont Mesa blvd in San Diego is. THAT was the system that made a believer out of me. It had the MG20.1s and a host of Levinson amps which sounded like you could walk around each performer on the stage...Ok, back to my system: vocals (esp female) sound very open and airy (trade mark of Maggies). Fiona Apple’s "slow like honey" is worth the price of admission alone. But alas just as others have said the big cat Maggies really need large, open spaces to truly shine. I have a 30x40 garage I’m dying to empty out and set up my system in, perhaps this Summer; we’ll see. https://audiostuff.shutterfly.com/

If you have 20.1, the no-brainer answer for tubes is ARC.

I use auto-formers with Maggies so it makes them easier to drive, but the big ARC amps will have no problem.

Frankly, to get what you want, I would go full ARC with the preamp and DAC too.  Go fully balanced to gain extra db and other advantages that will mate well with most ARC tube amps (some of which are strictly balanced).

Maggies and ARC electronics are ideal combo...but one other thing that expands the soundstage is...believe it or not...a great sub with Maggies.  A properly mated sub adds much more than just subterranean bass.  REL did a great demo at CES...Even with reference Rockport speakers, the subs added a level of ambiance and scale that recreated more of the recording space.

I don't know if they would drive your speakers, but you will not find a better tube amp than the Thrax Spartacus monoblocks.

Your best value and bet will be the 125 watt M-125 monobloc amps from tubes4hifi.  You can buy them assembled and ready to play for about $2800 plus shipping.  If you like to get your hands dirty, they'll also sell them to you as a kit for about $1800, minus tubes.

http://www.tubes4hifi.com/bob.htm#M125

I've been looking at a pair of PrimaLuna Prologue Premium monoblocks on AG for $2,800.  With KT120's they are 80W/ch.  Maybe bi-amping the Maggies is in order.  Keep the Accuphase for the bass, and PrimaLuna tube amps for midrange/treble.  Or maybe the PrimaLuna's alone will power the speakers.