I have a MSI twin frozr III and I can certainly vouch for it's quitness. I would say that it is pretty much silent. Even under load the fan never ramps up beyond the noise of my case fans (which are a pair of Noctua P12s) so if you want silence you'll get what you want with the MSI card. Temps are also good, for the most part remaining under 60C.
However, my card does not overclock well at all. It might just be mine though and AFAIK the GPU brand shouldn't affect the ability of the chip to run at higher frequencies, unless they hand pick good chips. In this case they would almost certainly advertise this as it is a costly procedure.