I recently bought Opeth - Still Life Special Edition which contains a 5.1 mix of the album on a DVD. It sounds awesome and is one of Opeth's best albums.
There is also a Pig Destroyer album called Terrifyer that has a second DVD with a 32 minute song in surround sound. I bought this one also, but I had never heard Pig Destroyer previously. I hated what I listened to of it though.
I know they're not SACDs or a DVD-Audio discs, but they are metal albums in surround sound.
Here are a couple others: http://www.metalinsider.net/geeking-...d-sound-albums
I can't recommend Opeth's Still Life Special Edition enough though. I also own Opeth's Special Edition releases of Watershed and Ghost Reveries, but those two are not anywhere near as heavy and brutal sounding as Still Life. If you've never heard Opeth I recommend Still Life as a great starting point.