My MDD is now more or less finished. All fans have been replaced with Evercool fans that are controlled by the fan kext in OS X. This essentially means that they run at 5 volts most of the time but can ramp up if required. The spec is:
2x 1.5 Gigs (2 megs cache L3 per processor)
2x Raptor Raid Sata
Nvidia 7800 GT (AGP)
2x Watercooled Radiators.