Well here's the thing.
You don't need a great mobo to get great clocks from an E6600.
The best mobo right now overall for high FSB would be the P5B Deluxe or many of the P965 mobos, but since you don't need a high FSB to get a great OC out of the E6600, it doesn't matter as much.
The Intel Badaxe 2 does over 450 FSB now; it'd be a top contenter if money is no issue IMO.