Copland CTA-408 or Audio Research i/50 ?

thanks so much for your response!

Even considered Yamaha 1200/2200/3200.

I would recommend finding the speakers you love. The sound that moves you. Then swap electronics to support them. 
 

Depending on your values in sound, the I-50 does not have to be mated with extremely efficient speakers. I have heard it with Sonus Faber and Dynaudio speakers and it has sounded fantastic. To me fantastic means musical, detailed, with great and detailed bass. Now if you are looking for highlighted treble and slap in your face bass then this is not your amp…. And probably you do not want tubes.

But, I would audition speakers regardless of efficiency until you find the ones you really connect with. Then, if necessary swap electronics.