Speaker recommendation for married couple

Just as another option, you may want to look into the single driver full range speakers the likes of Omega or Decware. I've only heard a couple of their models like the Decware DNA and Omega 3XRS and the vocals sounded incredible. They need very little power to come to life but may not be aesthetically pleasing depending on your taste. One other thing to keep in mind is tubes tend to generate a lot of heat and with a room that size, especially in an attic, you may find them uncomfortable during warm days. Good luck.

I would still recommend the Vandersteen's. Johnny Rutan can give you a great system.
FWIW, I have the Vandy Treo's, 2w subs, and Atma-Sphere amp and preamp and think it is about as good as it gets.
Bob

@celo - hum....my wife has very muscial ears and she never thought Harbeth were flat with vocals. In fact, far from it, it was the one area she though the speakers were very good. Same here, I always enjoyed the vocals with the C7s. I'm wondering if you have another weakness in your chain.  Did you mention your current amp and source?  

Tekton Design's Lore speakers would please you.

The only way you will know the sound quality of a particular speaker is to change only the speaker with the same electronics.

I am not a Harbeth fan, I prefer ATC to Harbeth, but that is not the point, your mistake is thinking that you have to shop used.

We and other area dealers have demo products that you can purchase for less, and in that way you can still here a good representative sampling of products which is impossible to purchase that way on the used market. 

 Your best resource is to find a good dealer and demo a bunch of speakers in your price range that both you and your wife like. 

You also need to be cognizant of the electronics can change the sound therefore you should either bring your own electonics