I'm trying a PoC for RemoteFX and am having issues adding a 'RemoteFX Video Adapter' to my Win8 Enterprise VM. I'm working on section four of this link and just don't have the option to add the video adapter to the guest. HyperV sees the card and acknowledges that I can use it. I have verified I'm running Windows 8 Enterprise in the VM.
I'm running Server 2012 R2 DataCenter with the HyperV role and the card is a Quadro 2000.
My problem was I was trying to use a Gen2 VM instead of a Gen1. Creating a new VM based on Gen1 "hardware" fixed the issue.