Speaking of other options, there are less costly options than a whole server. I have been looking at products by a company called Thecus (
www.thecus.com), especially the N4100, a 4 disk SATA NAS box, RAID 5 capable, hot swap box. Seems like a nice box, but it's about $600 without drives. The literature says it supports drives up to 400GB, so that would be a RAID 5 array of just about 1TB formatted. the also make a 5 disk model with a hot-spare capability.
No, I don't work for them, just looking for alternatives for relatively low-cost NAS solutions.