F1a, very nice system. But, yes, the B&W's look a bit out of place. I see that you like pure, dynamic sound and I would guess that you are hearing the limits of the B&W's in terms of what you are looking for now. The problem I see is moving you too far into the lush speaker category; because your system is very pure in terms of space, but can err towards too clean in the upper mids, in a very subtle kind of way that takes a while to hear (and which I assume is why you are rolling Mullards, etc. in there). I think the Ref Veenas may be the way to go. So you know, I have not heard this speaker, so you should ask around with others, but I do know the sound of the company, and would guess, based on what HP said in the context of your system, that this might be a good speaker to go to next. The Wytechs could drive them, not too big, good designer and company known for speakers that play music not just sound-machines. And, if you don't like them, I don't think you'll get too hurt on resale, etc. (Living Voice is tougher to resell).
But if you really want my opinion, and you think - as in, know this about yourself - that you are looking for a speaker for the very long haul, then I would look at scamming a pair of ESP Concert Grands (Esoteric Speaker Products) here on the 'Gon. They are big, esoteric, and hard to sell/ship, but they exactly fit what you want - they play gorgeous on classical and particularly do mid to low volume well, in addition to high spl's if that is your itch that day (I would then unload the REL, so you'd gain that space). I say, big, but also they have, from the front view, a narrow baffle profile. Its an end-point purchase. The new ones are $36K, but I saw one hanging around here for $20, and you could probably get them down to $17K. The big dealers won't carry them because they musically embarrass other more costly speakers and Sean McGaughan, the designer, doesn't care about playing the hi-end mag game and so won't poney up a big ad buy to get the big NY/CA dealer's attention to make it worth for them, financially speaking. He's another Mick Maloney.
Now, here's the additional rub: you'll need at least 50W to run them - which brings in consideration of your Wytechs, which would have to go at 17W...
And since, given your system (the Wytechs and Supra pre have similiar signatures and, I would assume, mate well), I don't think you want to move the Wytechs from where they are at. Hence, my original recommendation of the Veenas or Dudley's Audio Notes...
So, if it were me, I'd find some guys around you who have some Audio Notes and Veenas and go listen to them, and listen to see if their designer is hearing what you hear. I personally would go for the Audio Notes, but speakers are a very individual choice and I think you might very well prefer the Veenas given your preferences and coming off the B&W's (and the Veenas are nicer looking to boot, IMHO). In any event, I'm not sure either speaker will cuddle up to the REL, hard to say. Might be OK with the Veenas, but I would be surprised if the Audio Notes took a shine to a sub.
Let us know what you end up doing. You have good ears and a nice system and I'd really be interested in which way you go and what you think when you get there. Good luck!!
