Replacement GPU for a loud ATI Radeon HD 2600 XT

My GPU has been getting louder and louder. I've kept it clean, even sprayed a little silicone lubricant in there to little avail.

Here's what it sounds like: http://www.youtube.com/watch?v=HlWRPN1Z2N0

What would be a good quiet / cheap replacement? I need dual-dvi, PCIe, and mac-compatibility.