Joseph, this is a good point, thanks.
Primarily we are talking NFS/SSH/SFTP. Also possibly Samba, CIFS.
Like I said, a storage platform, nothing fancy.
While I have built many, I can tell you that buying a turnkey solution is *always* worth it if its mission critical. When you piece something together, you are always in for potential surprises and other caveats.
Like the rest have stated, I can only say that you haven't mentioned how busy it will be. That might dictate which type of sata drives or sas for example.
Whatever you do, get a good controller with nvram. I have a lot of LSI and while they are rock solid, the gui is a piece of sh!t and full of bugs. I always use the cli unless not possible.
Frankly, I always hated Adaptec, but I have seen mention of them making some sas controllers that performed better that lsi? Take that w/ a grain of salt, but next controller I buy, I am shopping around...
jlc