Modern speaker for Clayton amp

I acquired a Clayton S40 (SS, Class A) amp a couple years back and am now looking to upgrade to a pair of speakers that can properly utilize it. Am looking for advice on something newer, but am wary about what to pair with it. It can drive anything, but I don't have a lot of data points. Pairings I know worked a decade ago:

1) Audio Physic gear, hard to find newly used, very pricey new
2) Dynaudio - Older 1.3SE, S25, but I really don't know how newer Contours/Focus compare
3) Quads/electostatics, but imagine they're really pricey

Am shooting for the ~$3K range, maybe $5K if I could be convinced I'd go 10 years with them.

Speakers I like, but no idea what they'd be like paired to the S40:
Devore, Harbeth (too pricey)
Audio Note AN series (no mucking about, put it against the wall)
Triangle

Friends have suggested Zu, Tannoy and Maggies. Didn't like Zu, probably can't sample Tannoy (SF bay) and would love Maggies but don't want to add a sub to this.

Rock, folk, jazz, blues listener. Listening room is 20'x15'x10' and I can't go bass crazy, but would like to get into the 40Hz range on weekends

Thanks