I can definitely recommend the Red Wine Signature 30, and I'm sure the Signature 70 is even better. My speakers aren't the Zu's (I have Bastanis Prometheus MKI), but they're similar in design approach and they sound absolutely amazing driven by the Sig 30. It's a wonderfully involving sound that I'm absolutely thrilled with and my amp only has a few dozen hours on it so far.
Anyway I'd definitely suggest you go to Barcelona to check out the Zu's, it's easy to get to from Portugal and besides it's one of the best cities in the world :). I flew Vueling from Lisboa to Barcelona last year and I think the total round trip cost was less than a hundred euros. Much cheaper than shipping would be for a demo pair.
Gary
Anyway I'd definitely suggest you go to Barcelona to check out the Zu's, it's easy to get to from Portugal and besides it's one of the best cities in the world :). I flew Vueling from Lisboa to Barcelona last year and I think the total round trip cost was less than a hundred euros. Much cheaper than shipping would be for a demo pair.
Gary