I'm with General Septem here, turn your drives around and run the cables around the drive bay instead of through. I manages to get 5 drives in my acrylic case with a HUGE gap by doing this.
Try using angry_games' templates and adding a fan or two to your side panel... I had one, and wasn't happy so added another, both blow right on my 7900GTXs... those with the one in the front blowing right through the gap have severely decreased my GPU temps... and stability!
Don't buy something unless you really need it and are unhappy with your current case (i say this a couple weeks after spending over a grand on my rig that I didn't need :-)

