Originally Posted by Noctizzle
im also looking into doing this. Im worried that my 6870x2 Wont fit into the case though as its a MONSTER of a card
I would go for 7870, you can get these as short as 215 mm and if you so desire, some of these can be modded down to 1 slot.
I have http://www.club-3d.com/index.php/products/reader.en/product/radeon-hd-7870-eyefinity-6.html
and I talked to the Club3D support about warranty conditions and aftermarket cooling - they told me that I can dremel off half the holding bracked if I like and it will not void the warranty as bracked is not an "essential part of the card" so you can cut it down to single slot if you pick a suitable waterblock for it. I have a http://www.aquatuning.de/product_info.php/info/p13597_Watercool-HEATKILLER--GPU-X--Core-LC.html
here at my desk waiting to get a new res back from RMA to go into the card and into my loop. Perhaps in a week or two, depending on the shipping speeds (international shipping for that RMA). Also the card is not voltage locked and overcloking will not void the warranty according to the club3D support rep. He just told me to use adequate cooling if overcloking and overvolting
I have very tight fit in my case so I could use up to 240mm long card.