confused and don't know what to do

When I accidentally destroyed all of my electronics, I decided on the B&W 804 as my test speaker, thinking it would be the closest to my older 803's, and I was not wrong.  You are going to get a lot of advice, but here is mine, after listening to current 804's for hours.  STAY THE HELL AWAY FROM RECEIVERS AND ROTEL ELECTRONICS!  There are several B&W dealers from my home town to where I live now, and I have heard these speakers extensively.  Not one receiver nor the best Rotel electronics was listenable for more than a few minutes.  Even the salesmen at Best Buy Magnolia, who put up with me very graciously, admitted that I would not ever get a receiver or their Rotel stuff to sound as good as what I had, and of course I would have to bite the bullet and buy their McIntosh stuff.  The several high end dealers had some really expensive solutions, but here is what I think:  Go to a thrift shop or eBay and buy a cheap receiver and get some older, used B&W's for your surround.  Hell, I even bought a supposedly really well regarded, trade in  Marantz surround receiver from a Linn dealer in my town, just to use temporarily. After setting it up, I listened, then immediately re-boxed it, using just that one time.   You can have it cheaply, but only if you don't have audiophiles dying in your area where a decent receiver will appear.  Don't waste you money on current 804's to use a receiver.  There is not enough room in the box to put a big power supply.  Ditto for the few integrated amps I heard.   BTW, I have one large room. The stereo is placed where it sounds the best; the television is 90 degrees to the right, happily powering my much older B&W's, with same model line, smaller eBay B&W's for the rear.  Luckily, I found an aging Austrian guy to repair my Audire electronics, despite no schematics ever having been released.  Thank you Chris from Audio Advisors for that lead.

I have two homes with three separate systems in each. A home theater setup, a computer desk setup, and in my main home an audiophile setup, at the other a bedroom setup.
If you have listened to the 804s and like them, fine. You can get the appropriate center channel and get 805s for surround. Subwoofers should be REL, a pair of them, T/7i or T/9i. Anthem would be a great choice for this setup, either an AVM 60 Preamp Processor with an appropriate power amp or one of their AVM Receivers. Preferably the former. The Anthem gear comes with everything you need to get the most out of your room and gear.
Marantz works as well, but I have been using Anthem gear for over ten years and I am sold on it.
You are going to get a lot of hysterical posts responding to your question. The advice I have given you is based on years of satisfaction with similar speakers and gear. PM me if you would like details. This would be a solid setup you can calmly enjoy and build on if desired for many years.

I had the same conundrum Raw and solved it by putting in a McIntosh 8900 integrated amplifier with HT pass through. I have 804D3s as my main speakers and an older HT7 center channel and two B&W in-wall surrounds. I run a Marantz AV processor and multi-channel amp for TV/Movies.  This setup gives me the best of both worlds. I am a music first guy, so when I was upgrading from my older mid-fi system, the emphasis was on stereo reproduction and not Theater.  I do agree that the 804D3s can be bright and after hearing a pair of Sonus Faber Olympicas, I am considering a swap.  
I think this route is a very good way to go as the better integrated amps of today are really hard to beat.  Good luck. 

I recently purchased a Naim Star and B&W 702 S2’s for music and love it.  Plan on purchasing the B&W sound bar and subwoofer for my oled tv.  I think you can add rears too if you want a surround sound.  I tried to do what you wanted to do but there was just too much compromise on the audio side.

As your room is a challenge with all the hard reflective surfaces, a surround system with multiple speakers could end up sounding very muddled. I recommend just doing a 2-channel system, which will be easier to get sounding right and be a lot more immersive for watching movies than a poorly designed surround system. You will also reduce the amount of ugly wires and hardware. For amplification, if you do go for the B&W, I recommend looking at the integrated amps by Yamaha, Luxman and McIntosh. Best of luck with it!