Well, he stated that his preference is Sapphire over XFS. If that is his question, I personally would go with XFS over Sapphire! Only problem, I don't think XFS makes a 5850, you have to go with either the 5830 (which is over priced right now IMHO) or a 5870, which is quite a bit more than he may be wanting to budget.
Gigabyte makes a 5850 with dual fans, which seems to have a few favorable reviews, for what that is worth. I would tend to think 2 fans could run slower, be quieter, and do a great job of cooling myself. Hmmm, I may have to look a tossing a couple of those in my rig for Crossfire, now that I really start looking at them!http://www.newegg.com/Product/Product.aspx?Item=N82E16814125318