Super Efficent Home Theater Speakers

I was considering building a Home Theater setup around the Antique Sound Lab Wave tube-amp's. These are pretty good sounding little tube amps, and I could get five mono-blocks for $500.

The issue with the Wave's is they have an incredibly low output (10 watts). For regular stereo music on highly efficent speakers they sound plenty loud enough in a small space. However, I am having a hard time finding super-efficent home-theater speaker setups.

Anyone have any suggestions on super-efficent, easy to drive home theater speakers? Thanks in advance!

Robert