Are Seagate hard drives really that unreliable? I'm looking at the $85 2TB Barracuda since it's about half the price of the WD Black equivalent, but the reviews almost all talk about failure.
They usually work well, but you would hate it if a hard drive failed. It's the most fragile part of a build and sucks if it breaks. Go for a smaller-storage WD Blue, then add on as you need.
I can't speak to everyone's experience, but here is mine:
I purchased two 3TB Seagate Barracudas 6 months ago and have been running them in a file server 24/7 since. I haven't had an issue.
Although, if you don't mind spending a bit extra, the WD Blacks have an awesome warranty. 5 years, no questions asked replacement warranty. WD literally freaks the fuck out when their Blacks fail.