Anthem MRX 740 8K as an upgrade to my Denon AVR-X3700H

I have a 7.2 system.  I drive my front speakers using pre-out to my 2 channel system amp that drives my 2 channel system speakers.  I have 2 more sets of floorstanders for side and rear.  2 self powered subs.  Pretty happy with the system. 

Thinking of the upgrade in the subject.  I'm much more well versed in 2 channel sound than AV systems and would appreciate comments. 

I like the same things in theatre however, clear, accurate, and powerful, and dynamic.

For a streamer, are there better options than my LG smart TV delivered to my HT receiver via ARC?  I don't see any discussion of HT specific streamers/decoders.  

Jerry