I'm really considering purchasing a NAS device for my home network and decided upon the Synology DS 712+ and the DS 212j. The DS 712+ is more higher end and offers some more capabilities than the cheaper DS 212j, but they are both 2-bay NAS devices, accommodating up to 2 4TB drives with great features. I plan to install two 3 TB hard drives (the second one for redundancy) for Time Machine backup for 4 Macs, Centralized Media Storage, and the occasional torrent download. Which of the two models should I get? Should I shell out an extra $300 for the DS 712+ or go with the cheaper DS 212j ? Also, where is a good place to buy the hard drives and which specific hard drives do you recommend? THANKS A LOT, any advice is appreciated !