Speaker suggestion for Lamm ML2.1 amps


Any suggestions for a higher efficiency/tube friendly impedance characteristics speakers for Lamm ML2.1?
Thanks.
flyski
I should have mentioned, I have Wilson Sasha's and Lamm M1.2's right now. Superb combination. I just don't think the Sasha will be an easy speaker to drive for 18w amps with their rather low impedance that dips into 1.8 ohms.... Therefore I thought of a separate system for the ML2.1's with speakers they will be more comfortable with. Thanks for all the suggestions so far, gives me some ideas for sure.
The bigger Wilsons are much more efficient than WP8's or Sashas. You'll see the ML2.1's paired with Maxx's and Alexandrias often, and the reviews I have read make it clear they are one of the best matches, and best sounds that exist at any price.