Any way you can audition any of these combinations? Many dealers carry B&W and Mc and Rotel.
I had B&W CM4 with Rotel RB1080 and liked them, then upgraded to 804S and hated it (100% music, though), then moved to Mc tubes. The 804S are too resolving for the RB1080 and let me hear the shortcomings in amplification.
Clearly you have different priorities in terms of HT. Can you appreaciate the difference in sound with a lesser amp? Only you can answer that.
I know for fact the Mc MC252 sounded a lot better than RB1080, as it should, considering price differences.