I am on the Way to build a storage Array myself.Thinking of an
1U-Server with 3 x SoftwareRaid5 250Gig Disks and Fedora too.
Although it might be enought for now,i had the chance to expand it in
the future and save some money yet.

Watch cooling:
o Try to go for a case with 40x20mm fans over 40x10mm fans
---- ideal would be 40x28mm, but they tend to be noisy - 40-46dB(A)
o Ideally consider 2U if not space (price) constrained re Coloco
---- easier to cool - 80mm fans over 40mm

Watch PSU:
o To the original poster & any multi-GB system, PSU matters
---- not just re s/w failure, but h/w failure
---- very rare, but this IS an area where over-capacity is an idea
o If going for 1U, consider 350-460W over 300W
---- yes, a good 300W will be fine
---- however the higher rated ones have better cooling (twin fans)

The ideal 1U PSU is one with 2x 40mm exhaust fans at one end,
with the IEC connector between them. Quite rare. At the minimum
get one with inlet & exhaust 40mm fan - good redundancy :-)

For multi-GB, Linux with a Journalling Filesystem is important.
Still not figured out how long a fsck on 2.8TB would take :-)
--
Dorothy Bradbury
www.dorothybradbury.co.uk for quiet Panaflo fans