Also, you need to be a little careful with higher sensitivity speakers. They make more of the incoming signal, 'amplify' things to a greater extent, if you will. If you choose an amplifier that doesn't have a particularly low noise floor, the speakers will be revealing/amplifying more of the noise that the amplifier/receiver is producing. Many speakers are designed to create a balance between various evils - it seems most manufacturers choose an efficiency of 87-90dB. One evil can be eliminated, but another evil is then usually pronounced.
The issue probably isn't as pronounced as when using higher efficiency horn speakers which are nearer 100dB sensitivity, but it is worth taking into account. Plug them into an amp, switch it on, and turn it up to 0dB - that will reveal how noisy the accompanying electronics are, and how much the speakers will be exaggerating the noise they produce.