Speaker - Room/size dilemma

Need some advice. Like many other (married) folks here, I'm trying to find a reasonable balance between room esthetics and sound quality. We listen to music in our living room. It's a 16'X18' room with a two-story ceiling that is almost 20' high. So the room is basically a large cube. The other challenge is the speakers need to be placed along the18' wall, roughly a foot or two away front the side and the back walls, basically near the corners since we have a fireplace in the middle of that wall. The couch will be about 15' away from the speakers. All in all, the speakers and the main listening position form a 15' equilateral triangle. I guess I'll need  to look for high dispersion speakers with good off-axis sound quality. Almost the opposite of what I have in there now which are ML Aerius i speakers. I still have the pair of Definitive Technologies BP20 speakers which I had originally purchased for this room and I think they better fit that application but I really prefer the clarity and focus of the MLs albeit with a much more constrained sweet spot. The MLs are being driven by a McIntosh MC2200 and I have the Def. Techs in another (smaller) room hooked up to a Vincent SP-331 hybrid amplifier. My bottom line question is what would be a decent option for this cubical size room, trying to stay within a $3K budget. The bi-polar design speakers seem to meet most of the requirements but sound a bit diffused to my taste. Anyone has experience with the newer/slimmer Def. Tech. tower models? What about the Magnepan 1.7? Thanks in advance.