I'll second Soliloquy as a great match. I've heard the Unico paired with two different pairs of 5.3's in both a room of about the same dimensions as you quote with 8' ceilings, as well as a much larger room with no close sidewalls and a 9' ceiling. That combination shined in both locations and did not overload the smaller room, though bass was definitely reinforced there. If anything I thought it a bit lacking in the low end without the side walls and corners. No experience with the 6.2's though, but I think the 5.3's produce a bit more low end (three drivers vs. two in a slightly larger enclosure). 6.2's may offer a bit more midrange nuance I'd bet. Regardless, my experience is that is a great match.
Marco
