I own CLS IIz. By far the absolute best amp, if you are going to spend that money and you can find them, Cary SLM-200 monoblocks. No subwoofer needed, they are awesome amps and go absolutely perfect with the CLS IIz. I run them off the 4 ohm tap even though these have a 2 ohm tap. Dynamics, detail, etc. Some people only care about the midrange and try to run them off of amps that arent suited for them. That is why you will hear sometimes bright, not dynamic, no bass. Balderdash I say. If you run them with the right amp, you will be amazed. I own Plinius SA250 mk iv and alos ran them off of Krell, Cary 805C and Quad 606. My Cary's are about 100 to 140 watts in Triode mode and have plenty of guts. You will get many opinions and I have a lot of experience. If you can find a pair of these with copper in oil caps, you will not find anything better. This is my opinion, I just cannot believe how incredible the SLM-200's are on everything. But if some amp would come close to perfection for these speakers, this is as close to it as you will get. I run a Cary SLP98P with Teflon caps which is a great match.
Again, this is my 2 cents, but since you are considering buying amps without auditioning, I thought I would throw my opinion in.