What technical requirements need to be satisfied by a DVI KVM for these two Macs? I have a Mac Pro (2008 eight core 2.8 GHz), a MacBook Air (mid-2011 Core i5 1.7 GHz), and a 30" Apple cinema display (maximum resolution 2560x1600). I have a mini displayport to dual-link DVI adapter for the MacBook Air.

I want to set up the cinema display with a 2-port DVI KVM that fully supports both of these machines, ideally with ports for both DVI and USB.

What are the technical requirements I need to know about to ensure full compatibility with my hardware? Is it possible that some DVI KVM products would not support the maximum resolution of my cinema display?
I've used Teleport, a really neat pref-pane that functions as a software-only KVM switch. Moving the mouse off of one screen onto the next accomplishes the switch. I used to use it with a Macbook and an iMac next to each other on my desk, controlling either one with a single keyboard and mouse.