Suggested tube amp with First Sound Deluxe?

You are asking the wrong question. The First Sound will work fine with just about anything. Your decision should (must!) be driven by the speakers you are using.

You should match amp to speakers not preamp to amp.

To answer your question, try the Antique Sound Lab Hurricane amps. However, as others have noted, match the amps to the speakers. The Alon line works exceedingly well with the speakers, as noted by HP.

The speakers I'm considering (in order of preference) are Silverline Sonata III, Coincident Total Eclipse, Sonus Faber Cremona, Von Scheweikert VR-4.

I second the ASL Hurricane recommendation!