The duct just slides over the fan on the CPU Heatsink, don't have to remove the whole HSF each time! I used to be an engineer so I know how to drill and tap a hole, but don't have any taps anymore, nor a spare HSF! Seeing as it's just an experiment I don't forsee it being a permanent solution, rather a 'proof of concept'.
The PSU doesn't make any noise, it's a PC Power & Cooling SILENCER and is, well, silent
Also grafted a 120mm fan onto the VGA card as that uses passive cooling!
Just waiting for the finances to level out before buying a 'proper' solution