There are Zu dealers in Europe. In the United States, all sales are factory direct. Go to
http://www.zuaudio.blogspot.com/ for dealer locations.
I started with a pair of Druids and was very happy with their performance for music. The bass response justifies calling them full range speakers. My system is a 2 channel home theater, however, so I added one MiniMethod sub and found that to be ample for movies. I'm sure two subs would be better but I elected to upgrade to Definition Pros instead. With this speaker I have the equal of anything on the market today that will fit in a normal listening room and cost less than a new Mercedes. The bass is excellent, the dynamics electrifying and the resolution is among the best. The Definition is a fun speaker and the Pro version offers the option of choosing your own preferred bass amplification, higher quality woofers and the ability to custom contour your subwoofer reponse to the room.
Jim Smith, the man who introduced Avantgarde speakers to the U.S. market, has surrendered his franchise with them to become a Zu representative. As you know, Srajan felt that the Druids, by themselves, replaced his Avantgarde Duos with no real compromise of performance. When he moved to the Definition 1.5, he realized increased bass response and higher resolution than the already excellent Druids had provided. Then he accepted an offer to upgrade to the Definition Pro and has stayed there for about a year despite his ready access to virtually any other speaker manufactured today. I'm sorry I can't provide more in the way of actual head to head comparison.
In answer to your question about amplification, I get excellent results using a Red Wine Audio Signature 30 amplifier for the front drivers and an old NAD 2200 amplifier for the woofers. As you probably already know, the response below 50 hz can be infinitely shaped by the Rane PEQ 55 which ZU sells with the Def Pros.
The Red Wine Audio Signature 30 has been reviewed by Srajan and I know it is available with a battery charger that will operate on European current.
No one ever faults the Zu performance but some people find it difficult to get used to the sound of no crossover.
Good luck with your search. I don't mind if you contact me with additional questions. Srajan has always made time to talk with me and probably would do so for you, and Zu is known far and wide for being as helpful as they can be.
My room is 4.6 meters by 6.77 meters.