I would second the horn recommendation in general, and the Klipsch Cornwall recommendation in particular, unless you have a small room, then maybe something smaller in the Klipsch Heritage line. I have Cornwall II's that have 101dB efficiency. The very high efficiency is especially important if you want to experiment with SET amps. If you get speakers with this high efficiency, it almost won't matter what you drive them with, though, and the Cornwall's sound fantastic.
