Better question is............ why 3 cards?
3 way is really only good in internet videos, and ginormous screens.
Dual sli is more than enough,m plus saves you a ton of money.
But I think youre right, it'll need to be a full tower setup.
Can't recommend a case, but can say nless you like cutting, stay away from an Antec 1200
The only reason I went with the 965 is the 6pins. The 920 Only has 4 and the 965 has 3x6 pin and 3x6+2 pins to power my 3 cards, as they require 2x6pins each. Unless I read it wrong. haha, which is possible.
Hes talking bolut the i7, the 965 isn't worth the extra over the 920