I must agree, at least partially with Lugnut. Linn is onto something with the active systems, they are cumbersome, and difficult to rewire and move
should you need to, but the sound quality is there.
I run the 5140Bs for fronts and surrounds, and a 5120B for center, as well as a 5150 sub. FWIW I have always found them (5140s) to have much better bass than the Ninkas, which seemed to me to be a step down in the line. I am not sure if you need 2 or 3 amps to go active with the Ninkas, but would be inclined to go with the extra amp and buy the 5140bs, or even the older 5140s (difference is newer tweeter and better reinforcement of the case). As far as the Kelidhs, they are OK, but I would get the 5140s as they seem to show up for ~$1100 and are far superior. I even prefer the 5140s passive to the Kelidhs active
. But go active with the 5140s and you are in a whole new arena!
Now if you want to go to Keltics
. Up the ante a bunch!