Hi
I can't say anything about the BD player as I use a PS4 myself (Netflix, MediaPlayer, BD etc runs through it). Marantz and Klipsch speakers are a good match. I have them myself in my living room, albeit in 7.1.2. Whether the two Atmos speakers are necessary is a matter of debate and depends very much on the living room (ceiling height, ceiling composition, sitting position, distance to the speakers, etc.). In any case, I would buy my system again immediately :-)
Regards
F