Seeking advice. Integrating surround with a stereo system

First thanks for reading. If you have some opinion about this subject then leave a comment.

Let me set the scene:
  • Marantz AV8805 surround processor.
  • 2 x Emotiva XPA-5 gen.3
  • a homebuilt 20w power amp. for one of the dolby atmos channels. 
  • some very good speaker in a 7.4.1 setup
  • Tidal streaming with HEOS on a iPad.
  • PS3 for Blu-ray
  • LG 65C8 OLED
  • PS Audio Detect
  • Room treatment with absorbers and diffuseres. Carpet on the floor and heavy drapes.
My goal is simple, getting better sound. But how? Where should I start.
I have been thinking of buying a PrimaLuna integrated amp. But If I buy the amp I will also need to buy a streamer and a DAC plus interconnectors and some speaker cables. This is too much to buy at once.

Some options:
What do you think?
I struggled mightily with this one myself as my system is both high end serious listening audiophile and big screen projection cinemaphile. Huge amount of effort into both, really happy with the results with both too.

If I had to narrow it down to one crucial insight it would have to be when I realized all you have to do to have both with almost no compromises is set aside all the 5.1 HT propaganda. Then all of a sudden reality comes into focus and everything makes sense.

Like, doesn’t really good 2CH throw a deep wide soundstage with rock solid imaging? So then what do you need with a center channel? And subs? One never does work, what you need is a distributed bass array, which turns out to be better than anything the HT crowd has anyway. So the only thing you give up is some surround speakers, which let’s face it that’s a gimmick anyway.

Because, think about it, what is the goal anyway? Music or movies, same thing: suspension of disbelief. You want to feel you’re there. Well, what does that better? Lots of poorly reproduced sources? Or a few outstanding sources? You know the answer.

So what I have is a classic audiophile tube integrated driving two speakers with four Swarm type subs. Exactly like the Prima Luna you’re looking at. Sounds fantastic.

By now you should have learned what I did, that there are no home theater surround components capable of performance anywhere near what you can get for the same money in stereo. None. So all you have to do is give up on the marketing crap they’ve been feeding you that you need all these channels. That’s all. And everything falls into place.

A Luxman integrated will work. It has a "separate feature."

Consider, as an example. an Anthem MRX x20 with both pre and speaker outs.
You can run L and R line level to the Luxman amp in. Use the x20 for all other channels. Anthem's room correction functions normally.

Alternatively, get a pure processor and add additional amps as necessary.
The AV8805 is a pure surround processor
Hey Martin,
What I meant was, you can do the same idea I mentioned using a 2 channel integrated that has external  inputs + either a multichannel receiver or processor.