One of the things I got was a Dell Optiplex 3020. There were couple issues with this though, first was that the seller did not include a caddy for the hard drive.
Another was that the video was off of a Dsiplay Port, when connected to my new screen it was flaky. Not crisp.
I installed an video card, but it could not support more than 1080P.
Another thing that was weird was it needed UEFI or something similar.