In Medieval 2 total war, when you have a middle eastern city like Antioch, with a full army inside. outside are 2 or 3 full size mongol armies. you just know your boned.
space wise they should fit, you wont be able to put any other cards in like a sound card if you choose to do that later. i had dual 8800gts's in a antec 900 case on a similar motherboard. fitted in but very tight.