I'm not the expert! Your dealer should be.
I for one should link all equipment via master link (ML). All speakers without audio in the same room linked to the B&O eye and ML.
Make the BC2 master and BS4 slave. Your dealer knows how (I don't).
The CD and Radio functions will be locally. DVD and A.MEM are compatible.
Bonus is when your bro wants to listen to your CD. He just selects DVD.
Try to get your dealer to set up a BC2 and BS4 (NOT IN THE SAME ROOM) linked via ML.
He has all that it takes.