re: Looking for Media PC solution for multiple TVs

Just saw this thread. Apologies in advance b/c I'm a HT enthusiast and am going to ramble, lol. So I'll summarize a few points:

TLDR:
* NAS + Plex is a great suggestion
* Current gear is not 4K ready, you'll need to upgrade both the Pioneer receiver and Panasonic projector for that.
* Room sounds very good, you are lucky.
* Screen is "acoustically transparent" which is great. Def Tech speakers are good.
* Laser based projectors are not always "ultra short throw" that are placed right in front of the screen.
* There are lots of choices now for 4K projectors but the cheap ones won't take advantage of your great dark room.

I can tell from the note the previous owner left that this is a pretty nicely set up room and gives you a foundation for a terrific setup. I also knew immediately this was several years old as 9.3 is not an up to date audio format, but it's a VERY solid start. Current state of the art as someone mentioned is a 3 number format for Dolby Atmos / DTS-X where the middle number is height speakers. This is like 3D for audio - immersive sound. I have a 7.4.2 setup (7 = 3 front, 2 side and 2 rear surround; 4 = ceiling/height, 2 = dual subs) and would love to have a dedicated room to add 2 "front width" speakers for a 9.4.2. BTW, the big advantage of more than 1 sub is more even bass over multiple seating positions.

For the main question, yeah a NAS plus Plex is one of the most common setups. 4K streaming from Netflix etc. can be done via a Media PC or Roku, AppleTV, Fire, various other devices. But you'll need to upgrade both your receiver and projector for 4K, unfortunately. Panasonic never made a consumer 4K projector. Whether you want to replace the blu-ray player with a 4K UHD model depends on whether you plan to watch physical disks for 4K movies, but I would definitely look to upgrade to a 4K projector and receiver.

You have a good room that can take advantage of a quality projector, with the room being dark. One of the most important attributes of a great looking picture is good contrast, and the ability to have a really dark black level. That's a big deal for projectors - light on the screen is the "floor" for how dark you can get a movie scene. Think of a space or night time shot with a washed out grayish background.

Depending on budget there are a few projector choices. On the lower end starting around $1500 are several "simulated" 4K projectors that struggle to have good black levels. If you are wanting to do 4K the minimum recommendation I would have is about $3000 for an Epson Home Cinema 5050UB. If you can go higher, JVC makes fantastic 4K projectors starting at around $5K (RS-1000, discounted).

Someone mentioned laser projectors - lasers have started being used instead of bulbs in some projectors but the benefit for the added cost is questionable. Someone mentioned projectors being close to the screen - that's not the same as laser but some of them do use it. It's called Ultra Short Throw, and can be a great option but the use case is meant more for a TV replacement in a living room. Wouldn't work for your setup as it needs a cabinet right under the screen to be placed on.