You just need 3 largish televisions, a small TV or monitor for the top, and stuff to mount each screen in that configuration. Your PC doesn't need to be that good unless you are doing something like gaming, just enough to run 4 1080p windows. Once you connect them, it's fairly easy to adjust the configuration in Windows to extend and rotate the monitors to make the setup work. Depending on how you get the televisions (you can buy them used, flat screen 1080p TVs have been popular for a long time and are relatively affordable) and how you decide to mount them, you can build this setup for only a couple hundred