Right now an OCZ 1000W 80 Plus Gold, when I add the next 2 blades I'll add a 450W Booster X5 I had gotten for a yet unfinished multi-GPU machine, it has an auto switch to turn it on when the main PSU goes on, and I use the USB hub to power on the main PSU....

Edit: right now I don't have enough of the custom cables so the top right unit is powered with a 300W brick that came with my Vi-Dock for now.