No disrespect but you think Nissan make money on companies like Exedy, HKS, Blitz etc making clutches on their cars? You honestly think Nissan don't do something to a car because there plan is the car will be modified and some how they will make "MOST" of thier profits this way? So Nissan didn't put a $3000 triple plate carbon clutch into your R32 GTS4 not beacuse it would make no sense to do so on a car rated at 140kw, but because they knew you would modify it, go out and buy a super expensive 800HP clutch and this in turn would make them money?
I think you need to do a bit more research on the construction/engineering aspect of designing something.