which $1k used floorstanders for 35wpc tubes?

"After the very-heavy NHT speakers, I think I'm really sensitive to cabinet resonance (I returned a pair of Klipsches for this reason)

There is so much to choose from on this site, and $1,000 is A LOT to gamble with! Help!"

I know the NHT's fairly well. If you had a bigger amp, you would probably like them better. For what you are asking, the best speaker that I can think of is the Vandersteen Model 1. They're much easier to drive and I can't think of an area where the NHT's can beat them sonically. They may be able to play louder, but that's it. (Providing you have a more powerful amp). Overall, it will be a very big upgrade and you won't spend anywhere near $1000 for a good used pair.

((I think I'm really sensitive to cabinet resonance )))
The Vandersteen 1CI feature a sophisticated box less approach.
Their low diffraction multi enclosure driver mounting system should work for you, add to that phase and time aligned drivers and are an easy drive with low to Med power tube amps.
I use Quicksilver 25 WPC Mono Blocks with superb results Johnny Cash's voice sounds genuine,like it should, Beethoven flows with dimensionality,and takes string tone where box speakers don't go.
The speaker is well respected and owned by many top electronic manufactures.
I would read the 1CIs owners manual just to get an idea
of what their about.
JohnnyR
Vandersteen dealer.
http://www.tonepublications.com/review/vandersteen-1ci-loudspeakers/
http://vandersteen.com//media/files/Manuals/1cmanual.pdf

Omega loudspeakers

Monitor Audio Silver Series. RX6's can be had for well under a thousand used. RX8's might suit your room and music tastes better.