Since you have a tube amp already, and probably prefer its sound to solid state, perhaps you should consider trying a hybrid amp, as it combines the best of both worlds, great bass response (deep, tight and quick), with extended treble response and a nice touch of tube bloom to the mid-range. I went that way, and I doubt I will ever go back to either solid state or tube power amplifiers.
I highly recommend the Lamm M2.2 hybrid amplifier. It has 220 wpc into 8 ohms. It is a magnificient amplifier, and is better than any solid state amp I have heard (including the DarTZeel NHB-108 - although that might be becasue of its lower power, and the fact that it is a stereo amp), and it is better than any tube amp I have heard (bar one, the VAC Phi 300, which while it could not compete in the bass response, was better in the treble response, so I consider them to be equals). Used it probably runs about $11K, but you might get lucky, especially in this economy.
I own the Lamm M2.1 (200) hybrid amp, which is the predecessor to the M2.2. It is slighly dark sounding in comparison, but other than that it is identical sounding to the M2.2. (Note: by replacing the one stock Sovtek 6922 in each amp with some nice NOS tubes, such as the Amperex pinched waist tubes that I use, one can virtually eliminate slight dark sounding treble. I recommend replacing the tubes in the M2.2 as well, as the stock Sovtek tube is just okay, and a good NOS tube will make the amp sound better.) Used the M2.1 goes for between $7-8K.
My two cents worth.
Good Luck in your search.
