New speakers for $5000

Crutchfield has revel 226Bes on sale 
close to your 5k.  Maybe a middle ground, sonically?

and these Triangle Duetto Magellan 40th Anniversary

Are under 5k, without stands.  Might be great with the Luxman.  
And your room size is perfect for them. 

How about Graham speakers--maybe LS6 monitors?? Wonderful speakers.

Fully agree with @freediver. The M30.2 or .3 are perfect for jazz, blues and vocals. Had a pair for 5 years and compared them to the C7 and the  SHL5. They are one of the best stand mount speakers under 10k$. The Totem are also a good choice but with a different sound signature. If you go the Harbeth route, I suggest the Ton Trager stands. Tried different stands and this is the only one that maximizes full cabinet resonance of the Harbeth design. A match made in heaven IMHO. Good luck and keep us posted.

I have a Luxman L-509Z and just paired it with a set of Focal Aria EVO X2 speakers. It sounds absolutely glorious! The Luxman and the Focal speakers go great together. I'm running a Hana Umami Blue on a VPI Prime 21 going into a Sutherland 20/20 phono preamp. I'm also using a Balari SUT to run the cartridge at 47K ohms to get the volume up a little. The Umami Blue output is weak running as a moving coil in my system.

You might consider Fyne Audio speakers, which generally get good reviews.the F700 bookshelf and the F501 SP floorstanding both come in at $4800 a pair.  I have the F-702 floorstanding models, and they are simply superb in terms of tonal qualities and sound stage.  I am driving them with a Rogue audio tubed preamp and a pair of solid state monobloc amplifiers.  I think they are simply superb speakers.  I listen to classical, soft rock, vocalists from the 1940s to 1960s, music like CCR and the Moody Blues.  I have both a streamer using Tidal and a Thorens turntable for LPs,mincluding some “audiophile” LPs from the 1980s.