You didnt list it.. but I am very fond of my Giga-byte 7N400 Pro. Fast.. lots of features.. and VERY stable with my Barton 2500+ running at 3000+ and higher. When running at this speed, I am seeing my temp at about 35-37 Degrees.
The nforce chipsets generally work faster, and are more stable than the via chipsets. As far as the hsf goes, Amd's new fans are very good and also quiet. Some people have had problems with the holdown clip. They tend to loose thier tensile strength. If that happens to you, you might want to get a new fan, or just replace the clip. I tend to buy a lot of Asus boards, because they are reliable for me, but you hear great things about all of the nforce boards. The Asus ultra seems a bit better than the non ultra.
I'll go with A7N8X. Epox has a lot of features and it's good value for the price (about $40 less here in Argentina) but has no S/ATA controller and I'll be adding a S/ATA HD in the future so that's why I chose Asus.