Both are good ideas! A newer Gen cpu is never a bad thing in this hobby. Either method will do you good, so if you’d rather have the extra cpu horsepower of a newer cpu, you should go for it!
I have no opinion or knowledge of which Intel cpu is best for you besides “bigger number = more better” so hopefully the other responses with advice are accurate. Good luck!
If money is tight, then the cheapest solution would probably then be an nvidia GPU with NVENC support, since you wouldn’t have to upgrade anything to make it work (assuming it fits in your case of course) . I believe I managed to grab my 1050TI for about $100USD, and it supports many, many streams, especially with the NVENC unlock driver patch, and my cpu sits pretty at maybe 10% usage tops.
If you’re mainly using this server for plex, then a 13 series Intel with quicksync will be the way to go, from what I read the newest generation of quicksync is really good for transcodes. That and more RAM, can never have enough ram!
Is plex transcoding what’s making your server struggle? Even with older gens, I would think using hardware transcodes would keep the cpu load light. At least that’s what I noticed when I dropped an nvidia card into my server (no integrated graphics in my cpu)
I like the way you’ve explained the concept! I never could find the right word for it, I always thought of it as “meta” media, though that never seemed 100% right. “Reconstruction” is much better, it implies a more thorough understanding (and appreciation!) of the source material than mere meta-jokes. My concept of meta would lump Shaun of the Dead in with shit like Disaster Movie, which are obviously leagues apart.