Are there any KVM over IP switches that are not thousands of dollars? Ideally a 3-4 port switch for a few hundred seems reasonable to me.
Try this 8-port one from LevelOne:
http://global.level1.com/Business-Products/KVM-Switches---Extenders/Rackmoun...
It has an expansion slot which accepts a IP module:
http://download.level1.com/level1/manual/ACC-2000v1.0_UM.pdf
I use the base KVM, without the IP module, and it is very stable. It connects a USB keyboard and a USB mouse to USB and/or PS2 ports on the servers.
It is also cascadable.
I hope this helps.