go with the Nismo if you've got the money you wont be disappointed and its not really really obscenely loud,make your ears bleed going do the motorway loud.
my Zed s my daily driver and i do a fair whack of miles a day an i find its a lovely note and deep and burbuly when it needs to be.
and even better there just so happens to be a group buy going on atm as Ebized says ^^^