System forclassical music

Some friends are looking to upgrade their home stereo system from something that is probably 30 years old with in-wall speakers wired throughout their house.  They are classical music buffs, which makes me leery of giving them much advice (I prefer rock, female jazz vocalists and Argentine tango).  They are discerning listeners, but probably because of their current system their expectations were low - they really didn't think that a home system could come anywhere close to a concert hall experience until I streamed Chapotier's Te Deum from Qobuz on my (modest) system and their eyebrows went up.  I told them that they could reasonably do even better, but I really wouldn't know what to advise them.  I realized that I actually don't know a dealer I would trust sending them to!  Sad, but true.

So let's say a budget of $5 to $10K for a core system (streamer, DAC, amps, sub, speakers - TT and CD transport to be added later).  Integrated is fine.  Assume a 15x20 multi-purpose room (I alerted them to room correction, but first things first).  Any suggestions as to what might be a good fit for them?  Thanks.