Then you need 16tb of space.
1 Disk at 2tb = 8 bays on the qnap and so forth. 1 disk at 4tb = 4 disks
Not sure how big a disk we can get these days.
When you setup up the qnap it will still be simple.
With 4 disk these one will do you just fine. You can always contact qnap.
http://www.amazon.co.uk/QNAP-TS-410-...267346&sr=8-20