Good job you have avoided buying an nVidia card, unless you use KVM-VFIO or modify your card's hardware you cannot use nVidia cards for passthrough unless they are Quadro cards (https://bbs.archlinux.org/viewtopic.php?id=162768).
I like you used to always have ATI cards but since my Radeon 9800XT died I went to the nVidia camp. It is only recently after buying my gtx690 (yes the £1000 dual GPU card) and have nVidia make it so I cannot use tripple monitors with acceleration in Linux AND without modifying it be able to use VGA passthrough that I started to get very annoyed with nVidia.
Also their reluctance to help the nouveau project (the open source driver) has annoyed me too. AMD on the other hand have been providing information to the radeon project so I am thinking I will be moving back to the AMD camp for my future cards unless nVidia get their act together.
My current plan is to use KVM with VGA passthrough to run a Windows VM and use Steam Streaming to send Windows games across the network to my Linux and Mac computers. This way I can totally ditch windows on all of my machines while still being able to play my old windows games that don't have a Linux / Mac port.