Take a look at these: http://www.extron.com/product/product.aspx?id=dxphdmi&subtype=334&s=3
I have another one to look at, but I need to find it in my email. I will post back once I locate it. I spoke with quite a few about a year ago as we were extending workstations to remote stations (so the user couldn't gain access to the machine, so the next set of vendors may also take care of the Key and Mouse extension if you need it!) Be patient!