Is it possible to buy a decent tube amplifier in the $2000-3000 range?

Agree with the others that based on the stated specs of your speakers the 20 watt Quicksilver probably would not be an optimum match, therefore please allow me to recant.

Do what I've done - go hybrid.  I have a BAT 300xse integrated, 150 into 8 ohms, 300 watts into 4 ohms.  Very happy. 

I had a Pass X150.5 and a BAT VK3i tube preamp.  Very happy. 

Yes, I can see I need more power to run the speakers properly.

Check out Raven Audio out of Texas.  I have a higher end Reflection Amp but they have lower end and they use some great Russian Tubes.  The sound and power is great.  Call Dave Thomson, the owner, and discuss with him.  Also, they are designed as a show piece.  I get so many compliments on mine.