Sounds like you just need to do a case swap on the VRPC. A case w/o all the RGB gamer aesthetic solves most of your issues for about $50, since you already have decent hardware available.

For your use as a secondary system, not that I'm a Valve shill, but I kinda still suggest the Steam Deck... You wouldn't have to mount a secondary screen, since it's already built in, and it gives you the option to kick back however you want on the couch to play.

The amount of times I've sat on the couch playing on mine with one earbud in while my wife is watching TV is pretty significant, so a bit of asynchronous play would be available there as well. A small, black, zippered case can be tucked away a lot easier than a wall mounted swing arm as well.

I had looked into getting a Micro PC for a living room setup, but ended up getting the Steam Deck because it gave me more options for around the same price. I got mine about a year after they released & after getting it I realized I should have gotten it sooner.