Speaker suggestion for Lamm ML2.1 amps


Any suggestions for a higher efficiency/tube friendly impedance characteristics speakers for Lamm ML2.1?
Thanks.
flyski
Post removed 
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.