Need Sound Card & Reciever for PC, LG OLED65C9PUA, and Sonos 5.1 with Sonos Connect

[Daharen]

Okay, well I really was hoping to solve this problem through pass-through, but while I found solutions, they appear to only be in the industrial/pro-sumer space, and involve sophisticated EDID emulators that can merge the EDID audio qualities of one output with the EDID video qualities of another, allowing pass through without video loss. Since these solutions start at the $2,000.00 range, even though they are functionally just emulating things that should in theory be able to be done via software, they are less viable than the suggestions most people push of just getting a sound card and a receiver to allow for surround. I find this annoying, but that's my problem, and I concede the issue... 

Now my problem is needing to find an actual sound card and receiver that has any chance of successfully working with my configuration... I already know for a fact that one of the cables I need doesn't exist yet, and won't likely exist until later this year or Q1' 2020 (Display Port 1.4 to HDMI 2.1 adaptor). However, I want the rest of my system to be fully compatible for when that cable does become available. So here's what I'm looking for...

- Sound card must be able to output high quality sound that covers all the formats that a Sonos sound system is compatible with, https://musicpartners.sonos.com/node/464, https://support.sonos.com/s/article/79?language=en_US.
- Reciever must be able to process all compatible sound options, have HDMI 2.1 input and output so it can eventually handle 4k/120hz video pass-through along with audio decoding, and must also be able to fully utilize the 5.1 surround functions of the Sonos sound system, not just 2.1 sound, as that completely defeats the purpose at this point for me https://www.lg.com/us/tvs/lg-OLED55C9PUA-oled-4k-tv .

Based on my research so far this is not an easier set of requirements to fulfill than what I was looking for before anyway, it appears that no matter what avenue I go down this entire setup is doomed to fail, but here's hoping I just don't know what the hell I'm talking about. Any help would be appreciated.