Best speakers For ARC VT100MKII

Two questions:

#1: Describe the sound or performance you are seeking, as different goals and objectives (likes/dislikes) will play a significant factor.

#2: Have you done anything to maximize the performance of your room? A properly treated room will have a huge impact. You have invested in some very good equipment which can provide excellent performance. But it can also sound really crappy if the room isn't any good.

Vdosc, the Wilson W/P speakers will produce the goals of your indicated #3 (though I wouldn't call their midrange liquid). However, they will fail in your #2 category above. For your size room, they would be a good pairing with this amp assuming you listen at "reasonable" sound levels - though still loud.

I have owned Wilson (Currently), B&W (formerly) and Martin Logan (Quests I believe and Aerius, both formerly). Of these, the Wilson and ML's will deliver the best soundstage, imaging, etc. . . But I understand your feeling about the bass/panel integration seeming a bit like a powered sub.

Other considerations (based on my ownership):
Thiel - great at #3, but not enough power.
Totem - very good at #3, pretty accomodating for #2 and depending on model safe with this amp (try Forrest or Hawks)
VS VR4JR - pretty good with your amp, somewhat accomodating (but need space behind) for placement, pretty solid overall for your #3 - but the bass can get sloppy based on placement
Gemme Katana (or other models) - very good with your amp, quite accomodating in terms of placement, very good for your #3 category (with the notation that the sound stage is more behind the speakers than in front of them). But these would be a good match with your amp
I owned B&W's in the past, but to be honest, I grew bored with their characteristics (not that they are bad, just not what I was seeking).

But again, any speaker is limited in its performance based on the phsyical room it is contained. You cannot get tight/accurate bass and good imaging in an acoustically bad room!