look in the manual and see what it says about hooking up the card to 2B.
if you have the option to mount a fan on the side door, you can get one so it blows fresh air on to the GPU's that way to help cool down.
like this: http://i43.tinypic.com/209suvq.jpg
and static noice from the GPU to the sound card im not shure since im using onboard audio.

have you tested that card on a home cinnema setup? whit optic out?
im after a audiocard whit surround out on optics or else i have to use minijacks and phono cables from PC to reciever.

hey kkn. im also using the cosmos 2 . your orange color fans are cool. are they silent? what model and brand?

no im not using the cosmos2, i did a google on it and found in on pictures.
im using NZXT 810 switch bigtower.

The optimal configuration for 2-way SLI on the MVE is to use the 1st and 3rd slot. Since your GPU uses 3 slots, if you were to use that configuration, your cards will have no breathing room. The top card literally will be touching the bottom one and will pull in all the hot air from it. It doesn't matter how many fans you put close to it, it won't help. A fellow ROG user had this problem with his 2 GTX680's similar to your 3 slotted cards. Except his were the OCed version. In a gaming session, his top card got as high as 90C if I remember correctly. He could smell the plastic burning and the stickers from the fans were starting to deteriorate. Unfortunately he had the MVF which is limited on PCIe lanes.

So I would advise against using the default configuration. You're at a standpoint right now, my friend. What you can do is put the second GPU into the 4th slot and see if it works that way. If it does, you can have your SLI but you'd be giving up the Phoebus since the remaining available PCIe lane (Black one) is deactivated. Or you can get the 2 slot version of the GTX 680 from Asus and stick that into the 1st slot and the other 3 slot card can go into the 3rd slot. That way you have the breathing room for them.