I've got black ops 2 for the PC and the Xbox. Now since Ghosts has been released hardly any people play PC so I wouldn't recommend getting it. But you can use an xbox controller on the pc, it has to be wired I use my scuf controller. I've tried playing pc with a controller and I dont recommend it, there is no Auto Aim on the PC, so its incredibly hard to stay on target with the controller.
All you need is any wired microsoft 360 controller. Just plug and play, no need to install any programs or anything.