Printbus,
Methinks we need a nice clear schematic on how to wire the PS, board, bed and extruder heater and extra fans. An Electronics 101 grade diagram would suffice.

Would you expand on this: " You may want to keep the wiring to the heated bed lighter gauge than you'd normally want in order to pick up some resistance/voltage drop in the wiring. You could always consider adding a high-current diode or two in the heater circuit in order to drop the voltage down some," please. I know where you are coming from, but others may not have got experience in using resistors to set voltages.

OME