I had this kind of PC and upgraded from it.
I'd recommend a Ryzen anything > Intel. The Intel CPUs liked to overheat and go over power, and the performance simply wasn't there. Since it's 1080p, I'd highly recommend an AM4 build > an AM5 build. A 5800x3D would be perfect.
As for a GPU, anything like a GTX 1080 would be great. I had a GTX 1080 Mini. Undervolted with an i7-7700, I didn't go over 300W. All of that ran inside of an S4 Mini Classic, using a Dell 330W power brick.
I still have that PC if you're interested, but only if interested. It is finiky because of the undervolting, so there is that. It's been stable though with my setup, so if you follow it you're golden.