advise needed on amps...

Given your speakers, I wouldn't buy anything without first listening to it. If that means you have to wait or take some extra steps to somehow get a demo, then I think thats what you need to do.

If there is no way you can do a demo, I would still suggest that you be cautious. With speakers that sensitive its very easy to have gain issues that result in a hum or some type of similar type of noise. I have a pair of Wilson's that I sometimes put in my system and even though they are very efficient, a lot of the components I have tried with them don't work well because of this. The Zu's are much more efficient than my Wilsons. That would lead me to believe you might be in for the same problem; which was the reason for my first post.