Another new music room construction discussion...

I am fortunate to be building a new home with a cooperative spouse. I am constructing a room to house my two-channel music system which is completely separated from the rest of the interior with no shared walls or ceilings. Room basics and dimensions 21’ x 18’ x 10.5’ ceiling height. Concrete slab, probably manufactured wood flooring with rugs, sheet rock walls and ceiling. Dedicated circuit planned. Based on exterior relationship to the garage and backyard, the room configuration dictates that the speakers (Vienna Acoustic Mahlers- fairly large floorstanders) will be positioned along the long wall. They can be positioned equidistant from the side walls and positioned with some latitude relative to the back and side walls. As the room will be multi-purpose as a “man cave”. I will mount a 75” TV between the speakers on the long wall and my components will be housed in and on a nice BDI console that I own.
 I am soliciting opinions/recommendations for speaker placement in consideration of the above. I am aware of previous discussions here about the purported problems associated with placing my TV and components behind and between the speakers, but please accept that this is how it is being done, and maybe advise on methods to overcome the associated problems. Currently, no subwoofer(s) are employed in my music system, but I am open to advice on that subject as well.
System components for reference:
Vienna Acoustic speakers
Gold Note IS 1000 Deluxe Integrated/DAC/Streamer/Phono
Teres Model 245 TT, Rega RB 300 arm, Hana ML cart
Sony CD/SACD NS999ES as transport
Various audiophile-grade power cords and interconnects owned by me are available and Harmonic Technology 
Pro-Silway Plus bi-wire speaker cables used.

Sorry for the long intro. Eager to learn.
Scowler1, I've been doing some reading on something called the Haas effect.  It has to do with the relationship between time delay between two speakers and volume to compensate with 10 milliseconds (ms) being a peak for the effect.  Since sound travels at roughly 1 foot per ms, you need to put your speakers out from the walls so that the sound from the speakers has to travel far enough so that reflections are around 10ms late arriving at your ears.  At that time delay according to Haas the reflected sound should be down about 10dB.  You also need to make sure your speakers are equidistant from your head location when you are listening.  I use a thin (<1/8") old coax cable to compare the distance from chair to speaker left and right.  The cable is very flexible and light weight so it droops less and because it is wire based it resists stretching.  Be careful with anything fiber based like string, cord or rope as it will stretch and that introduces error.  It's the inter-channel time coherence that creates the superposition between L & R channels that becomes the illusion of a sound stage. That's what stereophonic recording is all about.  The illusion is in the recording and it's up to us to avoid screwing it up.  With that in mind you also need to consider the acoustics of your room to address standing waves and find the equilibrium point between reflecting surface area and absorbing surface area including diffusion where it is needed.  I don't know where that point is so you'll have to experiment and let your ears be your guide.  I use home made tube traps in my room and they work very well.  I have 12" diameter ones in each corner and 9" dia ones at about 3' intervals on the wall behind my speakers.  I also have a TV on the wall behind the speakers and my equipment cabinet between and behind my speakers and I agree that that's way it is and I'll live with the negative impact if any.  My previous listening room was almost the same size as yours with only 7.5' ceilings and I happily lived with it for 34 years.  It took me a couple of years of trial and error to get it working and then the slow tweaking process to get it dialed in.  Good luck and let us know how you are progressing.
There's nothing wrong with having equipment and even video between the speakers, for the simple reason there's more to good sound than any one single factor like that. My system is amazing, absolutely stunning imaging (read the comments) and its just like you're talking.

Its all a compromise and were I to move everything off to a side or something that requires massive spending on high quality wire, and money that could have been spent making something better is instead nearly wasted just on moving things further away. There is some improvement, yes, and I have heard it. Because I actually tried this stuff. So don't sweat it.  

But do try and locate your equipment in something other than a big flat monolithic cabinet. Its the reflection that causes that loses image focus so try and break it up and keep it as far back from the speakers as possible. 

The bit above about reflection timing is pretty good. It's actually more like 5ms than 10 but either way you are covered because putting them on the long wall means first reflections that are delayed way more than that.  

As for the rest of it, what you will find is its pointless to blather on about it because when the speakers and you are actually in the room it will be obvious the response back against the wall is crap, pulling them out improves immensely, and so does having your listening chair away from the back wall, and so all these distance problems solve themselves. 

Use one wire, one outlet, for the system. Another circuit for everything else. Depending on your budget it will be worth the effort to learn a little about acoustic design. I'm talking very, very basic stuff. Like how to frame a wall, 5/8" sheetrock blocks sound almost twice as effectively as 1/2", use a solid core door with weather stripping, even better one specifically designed for audio, things like that. A little knowledge goes a long way. 

That's at the budget end of it. What I did. Minimal cost, maximal benefit. There's also panels and construction techniques that can take a room to unbelievable levels of perfection. It all depends on your budget, time and energy. 

Ultimately though the main thing to keep in mind is it's a little like Mike Tyson, everyone has a plan until they get punched in the mouth. No matter how good your plan, still ultimately the sound you get is determined by the fine details of where and how you put things in the room. Perfect example of what I'm talking about, look at Mike Lavigne's system. Perfect example of unbelievable level of perfection. Yet for all the money, time and planning, it only got that way after Mike ripped out a lot and changed a lot more and then improved what he had changed.

It's a long road. Enjoy the ride.