SingleKVM Cheap Solution (Score 1)

You can use a Dual DVI, 4 port switch like SV431DD2DUA (which is cheaper then ATEN ). Hook up the MON1 and MON 2 to the outputs of the KVM. Use a 3 way splitter for the DVI of PC 1: INPUT1 PORT1, INPUT1 PORT3 and INPUT1 PORT4, The PC 2 is a straight connection to each of the DUAL DIV INPUT1/2 PORT2, Connect the DOC output using a splitter to INPUT2 PORT3 and INPUT2 PORT4. Connect the USB out from PORT1 and PORT3 to PC1 Connect the USB out from PORT2 to PC2 Connect the USB out from PORT4 to DOC. Now ports 3 and 4 have same video inputs and 2 different USB inputs. The audio can be source switched using Hot Keys. Easy peasy.... Good Luck