$20k top, full range speakers?

Oooh, that's a good choice. They're sensitive and the OP has a big room to fill.

Here's another possibility, and I've heard this setup:

A pair of Magnepan 20.1's plus a pair of JL subwoofers.

The JLs are extremely fast and musical and can keep up with panel speakers. These Maggies have a lot of radiating area and can move a lot of air. The subs provide bass to 20Hz or lower and extend the dynamic range at both ends of the spectrum. This is about the most listenable, musically satisfying speaker setup I've heard. Great imaging and soundstage, great cohesiveness. No boxiness, no bass resonant hump, no screechy highs, no overly forward midrange. Nothing syrupy or slow, no exaggerated zing of a fast but underdamped setup.

I think the Amatis would be great, if you're going to buy used. If you're looking for new speakers with a warranty, the Elipsas are on sale now for $15,800 in the US.

Crossover networks degrades the music! Crossoverless speakers sound much more musical! That's why I only listen to my BOSE 901 series 6 version 2's now!

The offer astonishing dynamic range at low levels, a trait that is inherent with Transmission line loudspeakers.

Can you explain why TL designs are so effective at lower levels?

What happens at higher levels - does the TL design compress dynamics?

Level8skier: I'm looking for some feedback on the Elipsa. Near impossible to listen to speakers in this price range these days. Any experience with them?