I know the R and the C use different pipes. I would think the R and the N would come closer to matching.
I can't tell you about the Hard chormes but Tapper had V&H on his C (I think that's what they are -the memory is the first to go) that I really liked, problem was the same pipes for the R didn't have the crossover. I counted that kind of important so I held off. I wound up putting Muzzies on mine. Look good - different sound. Nice but different. The V&H have a deeper throatier sound - mine are more of the old style glasspack sound. When you back off the throttle coming to a stop light it makes more of a snarling sound.(best way to describe it.) I've really come to love that sound.