For HT only use three good bookshelves for LCR with a good sub setup is probably better. For this application floorstanding speakers are mainly for looks or better 2.0 channel music use.
I respectfully disagree, those high ceilings, and near square room size, need bass frequencies to be well distributed! Capable towers are needed to anchor whatever number of channels OP intends to use. I adore 2 channel, and even 2.1 (and sometimes 2.2, sub in the back = surround sound
What kind of music do you enjoy? What percentage of the time do you spend listening vs watching?
Before you pull the trigger, I highly recommend you look in to Philharmonic Audio. The Phil 3's are one of the finest loudspeakers I have ever heard, at any price! They will have infinitely more bass output than the CM10's, and the high's are fatigue-free at ANY volume!
In 2-channel, with the cabinets open backed, and no padding on the ribbon, the dispersion is so wide that I have had to check several times that I was in Stereo and not running the center channel by accident.
Dennis Murphy frequents these forums, and is delightful to communicate with. I wrote a
review recently of a pair that I am still fortunate enough to be caretaker of.
And since you're itching now, I'd even say a pair of AA Monitors would partner perfectly with your receiver, and give you an introduction to the idea that there is much more to a speaker than it's name!