You should be fine with 140mm BD's. I don't know exactly where the measurements are taken on the C&D's, but in a tapered ski with a 3 point dimension, the first dimension should be the widest point in the tip? Also, a slight lack of ski coverage in the tip won't lead to any lost traction since the tip is rockered anyway. Many people cut their skins at an angle coming into the tip clip anyway.
Also, I highly recommend Black Diamond Ascensions.