I was thinking of getting the HIS H585F1GDG Radeon HD 5850, listed on neweeg, but I am totally open to any 5850 that would work. Not sure about the 12v part, pretty new to this. Thanks for the quick response.
Pop open your case and write down the numbers on the PSU-- or take a photo. Also.. what kind of computer? Preemptively I'm going to say that if its a Dell XPS it probably can run it fine, and if its an HP I would strongly recommend against it.