Can you explain what all would be needed to make a similar setup? I see the dongles for ~30 but does it need to be in a location with another piece of hardware or what?
For each connected device you need a dongle, which is what will plug into the display and usb ports of the server.
The TLDR is that manufactures don't follow specs as closely as you'd think, and as a KVM you have to handle the bugs of thousands of different manufactures for both upstream and downstream devices.