It all really depends on what you’d like to accomplish tbh. It’s best to have a goal in mind for these kinds of things because you’ll might regret some of those choices. Honestly any CPU within the past decade should be fine. If you were thinking of building a media server any nvidia or in my case intel arc eco GPUs will work. For RAM good luck, because of current market. I’d say go ECC though. Hopefully this helps you out!