Opinions and recommendations on active loudspeakers

With the exception of a very few, most active speakers are < $20K. Need more detail about the size of the listening space, type of music and how loud. Putting an ATC SCM 150ASL in a small room is pointless no matter what anyone says.

Maybe not the best, but Vandersteen Quatro Ct's will provide a great sound for the money.

Also trying to upgrade from my Sonus Faber Grand piano to something up. Looked at Sonus Olympica 3. Great but dear. Try it. Also looking at Kef and Focal Kanta 3. Found a new streaming outfit QoBuz. Believe they outclass any other

The Kii Three is awesome. 

I can see only one real advantage - you eliminate speaker cables from the chain. As for the best match for particular speakers - there is always a better match, including custom or customized amps. And it is hard if not completely impossible to deal with amps vibrating with speakers. This is a very flawed concept overall. The only kind of thing from pro audio world that is desirable is the source, when it is good, I mean. Audiophiles want sophisticated sound and generally are much more concerned with sound quality than pros. With some notable exceptions.
However, if the OP insists - just get top of the line ATC and call it a day.