Here is my build thread for the light. It will have all of the details. We used the Meanwell LDD drivers with StromX controllers for the dimming and programming. There are actually 4 x drivers for each 3 multi chips, 2 x 1000mA and 2 x 700mA. That picture is actually only 1/6th of the fixture. We had originally planned to power only 2 chips from the 4 drivers, but found that they could handle 3 of them, which saved us a lot of space.
http://www.reefcentral.com/forums/showthread.php?t=2505059