Agreed on the server. What exactly is the need for having that much data local? Or all the drives just older, smaller "legacy" disks you haven't consolidated? I'm trying to envision the use case for more than, say, 3 drives (OS/apps, swap, data) but just can't. Booting multiple OSes? Partition or go virtual. Lots of old drives? Consolidate onto a couple of 2TB units; it'd be way, way quieter and draw a lot less power.
Is there redundancy or a regular backup? I'd say get
this or one of it's brethren, add 2TB drives as needed, and move data over. Keep local the data you use frequently but dump everything else to the server. If it hasn't been touched in 6 months it gets moved. Dump the server in a closet or basement and let it worry about managing the data. Let it back up the workstation(s) a well so you don't need local RAID.