With the Clayton's I'd recommend speakers from Daedalus Audio. Lou is a big fan of the Clayton amps--I'm not sure if there is a manufacturer out there whose gear mates better with his stuff. I'm not sure about "inserting" the Daedalus in every once in a while since his Ulysses and DA-1.1's are quite large but you may decide the Salon I's are no longer needed once you hear what the Daedalus will do hooked up to your amps.
Go on and get a pair of single driver speakers (Cardersound Madison V2) and get a great 300B SET amp. I too have different speakers/amps for different moods. But, i find myself listening to my SET Single driver rig 80% of the time.
Love your Clayton M-300 amps, best SS out there, IMHO. I would consider some of the older Sonus Faber speakers, such as the Sonus Faber Guarnieri Homage over the Cremona.
I would also consider the Verity Audio Fidelio Encore or even the Parsifal Encore if budget allows. Both of these speakers would be a very welcome change of pace to your Revel Salon's, IMHO.
A small sub can sit silently in the corner when you're "Reveling" and you can find somme great small mains that are easily moved into place when you're not. Maggie MMGs and Ohm 100s are my choices to join a pair of Velodyne SPLR subs and an SMS-1 controller (the key!) when my Verity P/Es or Merlin VSMs are out of rotation. Very different way to go and fun to switch in and out.
Second for vintage, perhaps some redone EPI 100's with way cool inverted dome tweeters. It stops being fun when you're afraid to rest a potted plant, cold drink or lit cigarette on the cabinet.
Sonus Faber and Harbeth, yes. Both tend to be on the expensive side IMHO but it's not my budget, obviously, and if you're looking at those then, like John, I'd also say try Verity Audio. For a "fun" speaker my 2 cents says try Triangle.
Horn or a single driver speaker and some really lush tube amps.
As John Cleese of Monty Python used to say, "and now for something completely different..."
To have fun and not break the bank give Tyler a try. I own Kharmas and everytime I hear Tylers I enjoy the "MUSIC" they make. Peace and Good Listening.
To Shadorne: If your question was directed to me, yes, I do have a subwoofer. It is a big REL (the product name presently escapes me, but it was REL's penultimate model at the time I bought it).
To all, thank you for the ideas. Keep them coming.
Since you have a sub that closes one avenue to spice things up a bit. In that case, I'd pick the Harbeth Compact 7 from what you mentioned - a nice change of pace.
One reason I picked Ohm and Magnepan is that they offer a different radiating pattern (Omni and dipole, rspectively). If you're looking for a change up - like I was - this is one way to achieve it.
BTW - small floorstanders (no stands) are the easiest things to move in and out of position. IME, this becomes disproportionately important over time: The easier to move 'em, the more likely you'll actualy move 'em.
I own a pair of Salons and loved the sound but was dissatisfied with the bass, to me it was far from SOTA no matter where I positioned the speakers or what I drove them with. I have since added a pair of JL Fathom 113s to my system and look out! This is just what the doctor ordered. The Salons by themselves have very accurate bass, but I never could get it to integrate with the room. The JL with a Bryston crossover and lots of TLC have really transformed my system.
I've just ordered a Bryston crossover and a pair of 113s for the same reasons.
Want fun? Another harman product, JBL Control 29AV-1.
I have a pair of ste labs avatars that I think are amazing. They are super efficient(110db I think) but can still take up to 300 watts easy. The sound is amazingly clear and warm with full bass extension. No sub needed with these! I swear I hear things id never heard in songs before I bought these speaks. I have a full sonus faber 7.1 system for my home theater that sounds amazing too but it does not compare to the avatars imho. Fyi I'm using a jolida jd 1000rc integrated as a amp with them. The thing I like about these is that they sound SO real. They blow me away.