If you can swing Silverlines (17.5 or Sonatinas used) I think you'd be better off.Zu Druids are sensitive though folks love 'em or hate no fence sitters.And I don't know if they need big power but the DEQX controlled Emerald 3's are smaller version of CS2's everybody who reviewed and your room is huge so they might work since they are rated at 100db plus.Think if you could swing them they have 30 day return but given your tubed might not want digital processing.I want to hear them though.I have Odeon Tosca's horns/8" Audax woofered (94db sens) and they work but I was thinking of Silverlines being more balanced speaker.My horns are great for my primary jazz but large orchestra or when I want to rock they hare limited.Do Google search for high sensitivity speakers.Now I am going to look up Coincident myself for 15-30 watt Pass or T amp power.Miht dump my Ear 40 watt EL34.Tired of tubes for now but think T power might have something from reviews.I'll put tube in line section but have interest in high efficiency's myself
Chazz
Chazz