heh... PSU... man do I have some experience with that now

it was a journey down that road, but I am better for it now.
I would just advise going with a SINGLE RAIL power supply. multiple rails give your different "accounts" to take from. A single rail will give you one big "account" to take from. If your Hard drives are using 1 amp, why would u give them a 20 amp line? Your graphics cards may need more then 20 amps, so they will suffer, while your hard drives have all the extra current that could be allocated for the graphics just wasting.
I forgot about the fans, good call Vokl. If you get Coolermaster fans, they don't need a fan controller, they are VERY quiet on their own. Plus they come in a
4 pack in black or a
2 pack in blue