For stuff like this I refer people to a data destruction company which will incinerate the drives and then give a certificate back. One of my college buddies works at one in the Beltway area.
If you are looking to reconstitute the drives, I would say any DOD wipe tool should do it, they have some free ones with BartPE for example. Maybe pull each drive out and do a full wipe individually then put back into the san and low level the san on creation. ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
