Looking For Neutral Tube Amp Recommendation

Your description and speaker screams a great match for Atma-Sphere. The current mk III versions are best. The MA1 mkIII would be more than powerful enough for your speakers, and perhaps even the M60s would be a good match and save you money/energy/heat. Mate w/balanced preamp to get the most out of the design.
My Dehavilland Aries 845G would also be a good fit. They are SET, but more powerful than most SET, and mate well w/wide range of speakers. A tad sweeter mids than the Atmas, but still not euphonic like many tube amps. The newer model with the GM70 tube is even higher power if you don't mind a less common tube.
The Lamms are also a good choice.
Cheers,
Spencer

Until I hear better, I'll keep suggesting the Dodd mono blocks with all the upgrades. My room is about half your size but with about the same imp & eff speakers. My musical tastes are quite similar to your own too.

I doubt if i ever tax these amps. they sound great with even complicated musical passages, are dynamic and definitely involving. Easy to maintain, and inexpensive to roll tubes in or re-supply tubes too. Are a slam dunk budget wise used, and a quarter of the budget new. the newer ones reportedly have still more headroom. They are single ended only however, no XLRs. Very nice however.

Albert P could shed more light I suspect, on the Dodds.

Good luck

I think the answer to you question is the VAC 300.1 extremely
musical but very great low level detail.

Maybe even have a look at the amps that the german manufacturer audiovalve has out.

Without knowing more than your speaker specs I'll concur with the Atmas or used Lamm ML 2.1s. The Atma-Sphere MA-1s are neither inherently warm nor cool, they are very quick with extended highs and taut bass and music through them has a clarity of transparency that makes them worth a listen. The best rendition I've heard of female vocals has come through Atma-Sphere gear. The M-60s and MA-2s sound very similar to the MA-1s.