I know I am a bit late with this reply. My experience has been with the 6 blade fans and I have not suffered over heating which leads on to having a good radiator. Going back through service records fromthe factory quite a lot of cars came in to have the 4 blade fans replaced for 6.
Ben, I would leave the 6 blade fan alone until you have the car in regular use.If it didn’t have an electric fan prior to now, there is no great reason to fit one unless you intend spending a lot of time in hot traffic and the car struggles.If this turns out to be the case, you’ll find yourself fitting the 6 blade fan back on. Access to the points is not that bad esp. if you intend fitting electronic ignition. Far better to fit an unobtrusive electric fuel pump, which will eliminate the churning of the starter to get the fuel up to the mechanical pump.Also will help greatly in overcoming fuel vapourisation in warm conditions.