As Gordon has said the CLS need breathing room. They like at lest a 15 foot wide room to get them out to breath and give that HUGE sound stage. If they get to close you get a beaming sound. The huge opening on the one side will also play havoc with Stats. Cones do not have the rear wave to bounce all over and phase things up as bad. I like the Summit if you can get a cheap deal. The sound is INCREDIBLE. I listened to them in a smallish room with Audio Research tubs and was blown away. I think the older designs have merit but with the cost of the new stuff used its a no brainier. Don't get me wrong I love the classics like the Quest or Monolith. , I had a pair that I modded and sold to a guy in Toronto of all things. They just are GONNA NEED NEW PANELS. No two ways around it.
I also would look into room treatment. Its the single best investment that you can do. It can make or break a system.
I loved Summit when I listened to them in a show room, which was not much bigger than mine. My concern that opening as well as fireplace are only minor problems compared to the wall with the window (its not only bad geometry its also different reflective indexes).