So which one do you get? Well a few things to keep in mind. The motherboard supports 6 SATA hard drives and 2 IDE devices. So you should get a case that can support at least 8 drives.

The first case I tried was the Zalman GS1000, which is very nice looking, and can hold 8 hard drives. Unfortunately, I could not get ANY power supply plugs to reach the motherboard with this case.

I lucked out with the Antec 650 Titan EATX server case, because not only did it have a power supply mount near the motherboard power supply connectors, but the 650 W power supply ended up being perfect for my build.  How did I know that? I purchased a 1000W power supply first and mounted it into the Antec 650 case,  and I used a logging watt meter to measure the idle and peak watt usage while running IoStress on all hard drives  on the server.  IoStress pegged all 16 cores, and maxed out all 6 hard drives for a week. I checked the logged results — 520 W max usage.  The idle power consumption is less than 300W. Windows 7 does a good job at shutting down cores when they are not being used,  and the low power opterons help out alot.