ram config and cooling

Does anyone know if there is any disatvantage to running 8 chips of 4 megs each as opposed to running 4 chips of 8 megs to achieve 32 mb of ram? Im looking to run 32 megs of ram in a ASUS x79 sabertooth with an intel 3930k. Im thinking of using corsair vengence 1.35 volt, but it’s only available in 4meg chips at my dealer. I realize that this will fill up all of my ram slots, but is this the only disavantage? The 1.5 volt is available in 8 meg chips, but the general consensus seems to be to use low voltage ram. Also anyone have the corsair h80 cooler? I would like to get the H100 but it will be drama trying to fit it into my case. Looking on the web, it seems like the 3930k gets a little hot if you start overclocking.

thanks for any info