The case above indicated good. But it is better to take similar, but for 3.5 drives.
with the expander.
Roughly speaking the volume of one disk is now about 2.5 1TB, 3.5 4TB drives already there.
Controller type adapec 6405.
Processor purely for recoil xeon 5606 for the eyes. RAM is a good choice.
But you've got to understand that these servers better to take two, because if the disk will fly, rebild will be very very long!
To return eight threads easy to handle. The only need to specify the bitrate to not understand abut whether Gigabit port.