This isn't exactly the answer you are looking for but I hope my 2 cents can help either way...
I have a Sapphire 4870 and it's really quiet normally, however, every once in a while the fan kicks into a "turbo" mode for a second and it's pretty loud. Sounds pretty cool though so it doesnt' bother me but it may bother you. I have the feeling all the cards will be about the same in relation to noise levels though.
As for manufaturers, I chose the Sapphire because I've heard a lot of good things about them. As well, the guys at the store where I bought it also recommended it.