Well if the monitor you get has dual inputs, an analog and a digital, and the video card in the second PC had multiple outputs, you could do what I am doing. I 2 LCD's, with my main rig connected to both using digital outs. I have a second PC, connected to one of the monitors using the analog connection. I can simply switch the monitor from digital input, to analog input to switch the display to the second computer. You probably do what your trying if your bigger lcd had both analog and digital inputs. Granted, you would have to switch it via the monitor instead of just flipping a switch on a KVM, but it might work for what you're trying to accomplish.