Zieg, do you think the Yamaha RX-V379 is a decent starter receiver?
Oh dear! I seem to have started mission creep. If you are going to go a cut above a sound bar, which given the size of your room you are well advised to do, then you are correct to avoid HTIBS.
HTIBS of all flavors are bad news.
It is very hard to advise people on what they should get into. A big part of the problem is that the industry in many ways has progressively lost its way over the last 30 years, and it does not get better. Part of it is the misguided belief they are making things simpler and they are not.
The receiver is a good case in point. The function of a receiver is basically to be a switch to select inputs, digital audio conversion, processing, equalization and amplification to drive the speakers. Unfortunately there has been massive mission creep with a host of streaming options, and things like Musicast. Feature rich is what the industry calls it! The end result is that a lot of the budget is used up with licensing fees. Then not enough is left to build a decent product at the lower end of the market.
So the bottom line is that I advise members to buy at the mid price point of a range and up. Usually I steer people to Marantz, Denon and Yamaha. In your case you have a large room, so if you think you might actually want to progress to really good sound, you certainly need to consider buying a receiver with preouts, so you can add external amplification.
For your needs you are better off starting with higher quality bookshelf speakers rather then poor quality tower speakers. You will need a decent sub for that space and probably eventually two.
You are much better off starting to get the front stage good quality first and adding surround later. In fact if the front stage is really good, on most program the surround adds little. A lot of rooms are better off without surrounds. A really good front stage gives a wide deep sound field.
What is really required is good basic engineering with the core functions of units being top class. You really don't need streaming in receivers, disc players and TVs. Most of us end up with it in at least three units, when we don't need it. In my view they tend to be awkward and slow. Trouble is you can't steer clear of this nonsense.
Surfing the Internet is what computers do best. Chromecasting is brilliant, but has its limitations. When I stream it is usually computer based. Now with devices like the Intel NUC this is easy to do, with very small units indeed.
What all this duplication in units has done, is detract from core functions. This really amounts to jacking the price in pursuit of pointless versatility.
What I can say is this. Now that audio and video are joined at the hip, so to speak, then the case for good audio has never been greater. The audio is the equal half of good story telling, to say nothing of all the audio goodies now within easy reach. A good AV system in the home is an enormous pleasure, even if a luxury.
I have been at this for 60 years plus now. If there is one thing I have leaned it is to build a system patiently over time with good equipment. I have gear in regular use in this system that is over half a century old.
The next thing is that before ditching a good piece of gear for the latest feature, make sure it is really necessary. A case in point is 4K TVs. At a comfortable viewing distance for most rooms, it matters not one whit whether the screen is 2K or 4K. It would only matter if you had a big screen in a small bedroom or office.
Often times you can do an easy work around to extend the life of a piece of equipment. I bought my Marantz pre/pro for this studio in 2008. It has 4 HDMI inputs. Times change and now everything needs HDMI. So I added an HDMI switcher, so now I have 6 HDMI inputs. That's an upgrade at very low cost.
What I do know is that getting into the wrong gear is costly. So plan your strategy carefully, read and ask lots of questions.
You will do fine, as you seem prepared to listen to advice.
