I should start with speakers. This I know. I’d like to establish a new system.

It’s an extremely personal choice that’s not so different than choosing a favorite beer or who you think is beautiful. We can tell you what we like, but you’re the one in the executive decision seat. It’s very subjective.

Speakers are also quite room dependent (and system dependent). It’s wise to pick the speakers, then get an amp suitable for driving them. (I do like tubes) If possible, try as many in your home as you can. Used can be a great way to get the most for the money if the right deal comes along, but are harder to audition in your home...however, they tend to resell for close to what you paid, should you change your mind. Good local dealers are harder to come by than they were 20 years ago. Kits are another good option for getting a lot for the money, but are also difficult to try in home, and tend to not resell as easily.

The BBC sound leans toward a smoother rich more refined tone with subtle details. Horns are typically more lively and more efficient.

Some names you might consider that weren’t as common two decades ago - Joseph Audio, Usher, Sonus Faber, Fyne, Revel, Magico, Totem, Gershman. I’m sure others will offer more suggestions. Active powered subwoofers are plentiful now too, and are a great way to fill a large room with solid bottom octaves without having a monster main speaker, and can help the main speakers sound clearer by removing the responsibility of producing the lowest octaves. .

My advice is to buy what you love, but finding it is the hard part! Enjoy your search, and good luck!

When I did what you're doing, here in Denver, CO, I took the following approach:

* Joined an audio club. There are now people in my area to talk to and hear their systems, for free.

* Began asking questions on the forum. If you search my handle here, you can see that many of the questions I've posed are basic, informational. They may be helpful. 

* Visited local brick and mortar stores.

* Bought used at TMR and then returned a couple pairs (minus re-stocking fee).

These steps allowed me to develop a stronger sense of my preferences. Speakers first, then amp and preamp.

With $20k to work with you have set some lofty equipment goals. Source/cables/room acoustics/vibration control/power conditioning/equipment racks etc. are not throw away accessories. When buying used components condition/user history always surpasses cost. Consider dealer demo gear as a safer alternative. 

I ran a SLI-80 for a while.  It's a nice, solidly built integrated with plenty of power and lots of tube-rolling ability to tailor the sound to what you like.  I also like that there is factory support and service available from Cary.  Plus, it looks great.  Mine was an older version with the tube rectifiers so it had even more tubes, which I liked.

Returning to a hobby I abandoned two decades ago as life interfered with my personal desires.

I am currently drifting between horns or BBC sound. Two different worlds, but each intrigue me. Considering Volti Audio with Cary SLI80 Integrated while also Harbeth 40.2 with something like a VTL MB185 Series III. Schizophrenic I know.

Dedicated Room 12’W x 30’L x varied vaulted 11’H.

Your room is long enough where you can set up 1 pair of speakers on front wall and another pair of speakers on the backwall.

Rotate the chair 180 degrees everytime the schizophrenic hits.

Personally, I would ignore the BBC stuff and go with a) a horn and b) a panel llike a magnepan or something.