Which 7950 for two screens?

Solution
I have the Sapphire Vapor-X on my AMD rig and I love it. I have been running Sapphire GPU's for quite some time and have never had a problem with even one of them yet. As far as I am concerned Sapphire makes the best graphics cards. As far as OCing it I have not tried because I have not found a need to even try it. I run 3x Asus 27" monitors in a Eyefinity on my system and it works very well.
I have the Sapphire Vapor-X on my AMD rig and I love it. I have been running Sapphire GPU's for quite some time and have never had a problem with even one of them yet. As far as I am concerned Sapphire makes the best graphics cards. As far as OCing it I have not tried because I have not found a need to even try it. I run 3x Asus 27" monitors in a Eyefinity on my system and it works very well.
 
Solution
I also recommend the Sapphire Vapor-X version.

The voltage lock just limits overclocking beyond a certain point. It's a PROTECTION THING and something I recommend actually.

In reality it's unlikely over-volting would give you very much overclocking extra and the fan noise would jump significantly.