If you are planning on buying one of these bars, use @2KCruiser . Not only is using one of our own always a good thing, his customer service is absolutely outstanding. Dealt with some incredibly ridiculous UPS idiocy after ordering mine, and he made it right time and time again. Great product...
If you mean which one to upgrade then the rear hands down. Much more bang per buck for on road feel. Stock front and upgraded rear is a pretty common set up.