I'd like to move from internal drives to a NAS since my data storage needs now require it, and I'd like my data shared across my network. My data currently consists of a 2 TB iTunes Library (music/apps/video etc). Also I have about 2.5 TB of photos that I store as backups for members of my extended family. I'd also consider moving my ~500MB web server there. Room for expansion is always good as with data I am somewhat of a packrat.
I currently have an Ubuntu server hosting my web server (testing, not production), and a Mac Mini server hosting the photos. I have my iTunes library on my PC so you can see how having this all in one place, shared on a network, would sound attractive.
My first question is should I get a NAS and use iSCSI (or similar), or should I get storage that connects directly to my server using ESATA/USB/FireWire (maybe ThunderBolt o.O) and share it that way.
My second question is once the first is decided, which products should I consider? The most I'll pay is $1000 but I'd prefer something in the $600-800 range. I've already been looking at the QNAP TS-559 (Link).