Asking suggestion for $15,000 audio system for classical music

Save about 2-3K for room acoustic treatments. Contact GIK acoustics and talk to them about your rooms and options.

Great info ! Now we can begin

love all the posts recommendations for quarter mile cars when an enduro might be needed .... anyway

from a theoretical point your square room is probably the lesser sounding of the two but the odd shaped ceiling will most likely help a bit. The other larger room with high ceiling and openings will most likely sound better. Will they be furnished with living furniture, etc or the audiophile sterile dedicated room aesthetic?

i will check my Texas network for ideas on reputable dealers.

do you have much vinyl? What service do you use to stream ? Do you have any CD or SACD ?

have fun

You should also buy Jim Smiths most excellent book on getting better sound

Also @audiotroy  makes excellent points on the tried and true system approach to the problem. The larger room will probably require a bit more power all other things equal. 

And since you have a fantastic starting budget, put one of Charlie Miller’s tweaks in the budget, evaluation of the sonic differences by you in your room, your system, your tastes will tell you IF you want to go down that “ perfect path “