It seems to me you're complicating this setup.
I run 6 computers, 6 LCD's, hardware multiboxing.
You simply need the computers, the monitors, whatever keyboards/XKeys you desire (I have 3, including 1 footpedal), the Vetra multicaster, and a 2 port KVM, not an 8. Then on the computesr, you run software such as Octopus or Interbox to do your keyboard mouse sharing simply by moving your mouse to another screen, which is better than an 8 port KVM because you need to keep switching all the time. This way, 1 port of the KVM is a broadcasted keyboard, the other is a single routed keyboard directly to my main computer.
When I want to control just one, I hit the KVM hotkey, then move the mouse to whatever computer I want to control. Then when I'm done, I move my mouse to the main computer, switch the VKM to broadcast and go on my merry way.
You can see the setup I'm talking about here:
Pics of my 5 computer setup (now 6 computers as of 04/10)
