speakers for low listening levels/tube amp

I just bought a tube amp (a sophia baby) and am looking for speakers that match well. I listen to lots of acoustic music, some jazz and bossa nova and occasionally some heavier music like rush/pink floyd etc. Huge bass is not a big deal for me.

I'm most interested in speakers that sound rich and detailed at low volumes. Having 2 small children and living in a townhome, I listen a lot late at night and want a good soundstage without lots of volume.

I've considered Omega and the Cain abbys (the Cains look great but are a bit spendy for me). I also looked at Klipsch (RB35 and RB75). I'd like to spend in the range of $600, but could go higher. Of course lower is better and leaves more money for music.

Does anyone have any advice? Never having heard these and not having time to demo, I'll be buying blind so to speak.

Thanks!