so like ram, storage and like cpu in intel terms (basically the only one i could find and understand)
i will be using plasma bigscreen, running my jellyfin server, maybe play some steam games (decently light ones), maybe run a minecraft server, watch youtube, stream like netflix etc.
You are making a mistake.
Do not build one big computer to do everything.
The system requirements are wildly different for the different things you’re asking. That means your computer can’t make compromises to be cheap.
Jellyfin and the piracy stack will want a potato with middling amounts of ram and a cheap discrete gpu from six years ago. And whatever storage you plan on using.
Minecraft will want ram and fast cpu.
Streaming will want a recent cpu with all the bells and whistles and a remote.
Playing games needs a okay gpu.
When you combine all that you need an okay gpu, a recent fast processor, a good amount of ram and the rest of the stuff to make it a computer. Plus your time. That’s approaching $800 now.
If you split it up you can do jellyfin, the arrs and Minecraft server on a ten year old gaming pc of yore that someone thinks they screwed you on when you pay them $100 for at a yard sale and hook your tv to a dedicated streaming set top box that can talk to your jellyfin for $100.
Dealing with multiple computers is a pain (slow boot time and/or more power consumption and multiplied effort) and more expensive in most cases (you still need the minimum requirements of each part, but now there’s the rest of the each PC to get too).
I did it for power consumption; one small low power computer that’s on 24/7 for NAS + providing some services like home assistant, and a powerful computer for gaming, photo development, etc. I ended up being too lazy to boot up the powerful computer most of the time so I was doing less of what I like to do with it and my time spent on the computer was slower. I switched back to one do-it-all computer and I’m much happier.
The only reason I would want a multi-systems setup is if I need to run some things in the background that would make the computer unresponsive or unusable for some interactive tasks (e.g. local AI inference or training, video transcoding, heavy data transfers, …).
You can run several low power systems with lots of capabilities for less total power than one general purpose system. Now- at some point there are applications the low power systems are either annoyingly sluggish at, or altogether incapable of, but if you’re not getting into that kind of stuff, then a handful of small systems can be the ticket.
I built a wooden box with a filter and a big (200mm) fan and put 4 raspberry pis + a network switch in the filtered airflow, the pi that serves stream analysis on frigate has a co-processing hat, the rest lighter weight stuff like homeassistant, libre elec, and so on. Definitely more work to setup than a single Intel Core NUC - but also about the same or lower power under load, has been rock solid for years, and the filtered air setup has kept dust out much better than my series of dust strangled NUCs over the years have.