Steve,I listen to the Needles daily so you can imagine what I think about the sound. They do very well with a relaxed, uncompressed sound that continues even to high SPLs. Lots of detail in the treble with the ribbon tweets. They do need a subwoofer (two would be nice for a larger room) to cover the 30-120 Hz range.
The original Needles has an Aurum Cantus G3 tweeter that costs $330 a lick so you could do a lot better these days with a set of the Fountek Neo2.0's at $120 each.
Creative Sound Solutions (www.creativesound.ca) did offer a Needles kit but recently took it off their site. The kit was priced at $1000 per pair. CSS still have the drivers and the other parts are mundane. They offer the plans or you can contact me for help if you are serious.
Jim