Energy, Environment & High End Audio

How to get a great sounding amp without using a ton of energy? It seems I keep running into high energy guzzling amps when I pursue the sound I want. I'm currently running ProAc 2.5's with a Pass Aleph 3. Sounds pretty good, but actually a little bit forward (perhaps the speakers need more breaking in). Anyhow, I'm wanting to go for a slightly less harsh, more fluid sound, and am thinking of getting a tube amp to go with my Rogue 66 preamp. I'm thinking BAT, AR, Cary - around the $2K used level. My problem is that some of these amps run on near 1 kW - about the same a an electric hair dryer or space heater. I'm having problems justifying the power use, except in the winter when we need to heat the house (I live in Arizona). Questions:

1) Can anyone recommend good tube amps with the setup I describe above?

2) Overall, how do you deal with the power use question? Is there a point at which it becomes irresponsible to use so much juice for this passion?

Thanks. Peter S