This is a shameless plug, but it's also a direct reply to Q posted in the OP. Mod please delete as desired.
Since discovering the joys of speakers with sensitivity in the low-mid 90 dB range, it's my distinct opinion that systems with the highest value require no more than about 20-30 tube watts to play live music levels with uncompressed peaks. This being the case, there's absolutely nothing wrong with starting out with the amp and then considering speakers later.
I know
AudioKinesis Zephrin 46 plays live SPL with as little as 10-12 tube watts, because we displayed it with such amp a few weeks ago at Newport THE Show. Each channel/each enclosure of Zephrin 46 comprises two discreet speaker systems, each flat 16 Ohm above the bass range/12 Ohm minimum, with easy phase angles. The two 16 Ohm sections wire either parallel for 8 Ohm or series for 32 Ohm (think OTL amps, whose power increases with rising impedance).
As a matter of fact, in shopping for a tube amp for use in my studio to power Zephrin 46 and Dream Maker LCS, the lovely RM-10 Mk II nears the top of my short list.
$4900/pr including shipping MSRP Zephrin 46 falls one-half to one step behind the world's best electrostatic panels in pure detail and transparency. It's also behind it's bigger twice as costly
Dream Maker LCS brother in this respect. In every other parameter it excels, especially neutrality and spatial effects. One of it's most attractive features is wide array of user tuning features for spectral balance, room acoustics, and partnering components. The cherry on top is a unique, proprietary, electro-mechanical bass mode damping feature that functions in 3-dimensional space as opposed to line level EQ that worsens performance outside microphone test locations.
Zephrin 46 made TAS/Dr. Robert E. Greene's list of Top Five Speakers <$15k/pr at Newport THE Show. I have special pricing on both models for show demos in walnut. It may seem strange, but I think it's a reasonable proposition to ship one speaker, audition it in mono, and if it meets performance expectations, ship the other speaker. If not, return in like condition and buyer looses only return shipping. I wish I could remember the names, but over the years I've heard that some designers fine tune one speaker by itself before final tests in stereo.