I'm planning to put one of your dual 533MHz FSB Xeon motherboard in the SC762 chassis. There is an optional PII/ PIII Xeon Cooling Kit on the website for this chassis, do I need to buy it since the new motherboard uses the new Xeon?
No, you don't need to get the old PII/PIII Xeon Cooling kit. This Kit is for the old style Xeon which has passive CPU heatsink and need this cooling kit. The new Xeon motherboards come with CPU heatsink and it has fan on it already.