OK... To set things straight... I had the terminology wrong... A KVM is to let one mouse, keyboard, and video screen talk to multiple computers... What I'm trying to do is the opposite... One master computer (upstairs) with a "dumb terminal" in a downstairs room, about 100 ft away...
Yes, this functionality for the long keyboard, mouse, and video cables spoken of above is in addition to a home network with CAT6, CAT5, and RG-6 drops to each room of the house...