FirmTek ThunderTek/PX PCIe Thunderbolt Enclosure + Q6G 4-Port eSATA card
See the Thunderbolt area as well as the MPG transition to 2013 Mac Pro area.
MPG has five FirmTek multi-bay eSATA enclosures to contend with in the transition to the 2013 Mac Pro. These are high quality enclosures with hot swap trays and thus a big investment to preserve, not to mention many drives bolted into drive trays for those enclosures.
The FirmTek ThunderTek/PX Q6G makes the transitioning easy.