Classical Nirvana for 10-15K

I won't recommend a whole system. What I found the hardest to reproduce for great classical is the low bass detail to bring out the cello and string bass. Add a REL sub, which are real musical audiophile subs (not boom boom boxes). Get at least the Storm III. The cheaper Stratus III is also a nice sub, but does not go as low as the Storm. The extra money for the Storm or better is worth it in my opinion. In addition, the REL actually fills in the bottom of all instruments, which will increase the space and air between all the instruments.

I am not very familiar with the current crop of high end B&W subs. However the ASW-800 (the Matrix sub) was very very good, and was a great match for the Matrix 800 series. No reason to think the new ones would be any less. The REL's are usually a good match for most speaker lines.