Which amplifier

Can't go wrong with either, if you want warm, get Mac, if you want detail, and soundstage get Accuphase. Both will be amazing with your Klipsch speakers. 

I would pair a less warm amp with the Cornwalls, which are a bit warm on their own.  I’d go with the Accuphase.

I completely agree with @faustuss I have both of these amplifiers and I can confirm that they have too much power for Klipsch speakers, if you do not want to change speakers then I highly recommend Luxman SQ-N150 which is perfect for your speakers and has very good MM and MC phono input.

I own Mac amp and pre, but damn that Accuphase kit is pretty! 

@andu Voice of reason!