Just a quick update
Now running Vista 64 SP1 and it is amazing.
Got the visual setup I want (IE, looking like normalish windows instead of some fucked up crossbread between a mac and a pc) and the speed is amazing.
So far all my 32bit software has instaled backwards compatible and everything is running super smooth.
Even got a "windows compatibility score" of 5.5 - which should increase once my second gfx card arrives and is setup in "Crosshair" mode



Thanking you all for your advice and information - it was invaluable