Well I started looking around on all of the usual places for drivers that would work for your speaker project and boy oh boy, pickins look slim.

At Madisound I'm seeing the Markaudio Alpair 11 MS's would probably work, it is just a touch bigger in diameter, but would fit the face of the speaker baffle.

At Parts Express the pickings were just as slim. I saw the Dayton Point Source, but sure wouldn't recommend that to my worst enemy, total piece of crap.

Also at parts Express is a 5" Tang Band W5-2143 that is very interesting. I've had great luck with these drivers

I might spend some more time shopping around the less well known places and might find something interesting someplace.

Forgot to included this link that shows a cabinet used with the Lii Song drivers…
https://www.stereonet.com/forums/topic/528513-lii-song-fieke-s6-floor-standing-s...