My advice :
Don't power your system in more than 1 input !
Because when there will be a bad contact, i'll create a kind of resistor/capacitor that might destroy quicly your system...
That happened to a few people that powered their BPPC+GREX or Mediator by the "PCI" bus and floppy connector.
I only power my 1200 by the PSU plug on the bus.
I change my poor old 200 Watts AT PSU for a "modern" 420 W ATX PSU on my GREX. To make it start, I cut a paper clip,put one close to the GREEN ATX wire and the other one to the close BLACK ATX wire, and plug an old "TURBO" PC Switch to POWER ON/OFF like a normal PSU. :-)
(I'm waiting for MisterHardware answer about GREX1200 ATX chip)
