I like to invent and I would like to know

That friend, I would like to know if there are any motherboards that can be used with an i7 8700 and two RAM modules of 8GB every 1 that I want to take out of a broken iMac that I have, so I can connect my graphics card and mount a PC to catch. ?? BTW took the pieces out of the iMac because it rotates the screen.