which $1k used floorstanders for 35wpc tubes?

Thanks for looking! I need some speaker recommendations. I've got a 35 WPC tube amp (that I love) and my NHT VT-2s are underpowered by it, as well as not a very sensitive speaker.

I'd like to get a set of floor standing speakers for around $1k used (at most). My room is 15x20. I listen within 10 feet. I listen to every genre but am most picky about how my classical recordings sound. 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!