I'm considering either the new Haswell iMac or a new Mac Mini when they're announced. I have two 4 TB drives (one active, one backup) that I use to store photos on, which I work on in Lightroom (and increasingly rarely, Photoshop). I have a 2008 Mac Pro (3,1) and these drives are inside the tower, so I haven't had to worry about external storage. I'm wondering what my options are for external storage with the iMac or Mini. Since I won't be doing video or anything that requires crazy speed, would a USB 3.0 enclosure be enough? What would you recommend for an external enclosure that can hold two 4.0 TB drives?