There are many ways to accomplish what you wish to do, from changing the speakers, amp, preamp, source or even cables. Also, subtracting damping materials from the room and adding more reflective surfaces could also help liven up the sound.
I was faced with a similar dilemma several years ago, the speakers I bought sounded great in the dealer's showroom, but dead in my room. I called the dealer and talked about this, and it turns out he was using silver cables. I had tried silver cables a few times previously with no success, but when I tried them with these speakers they worked great.
As for your original question regarding amps, Bryston makes powerful SS amps that sound like what you are looking for.
I was faced with a similar dilemma several years ago, the speakers I bought sounded great in the dealer's showroom, but dead in my room. I called the dealer and talked about this, and it turns out he was using silver cables. I had tried silver cables a few times previously with no success, but when I tried them with these speakers they worked great.
As for your original question regarding amps, Bryston makes powerful SS amps that sound like what you are looking for.