Replying to 166 or 171 skis? +KKKKKKKKKKKKKKKKKKKK

I am 5'9" 140lbs and Im looking at the Stepups Afterbangs and Traveling Circuses. I am getting the TC's for everyday use around the mountain and in the park, hitting mid-sized jumps and jibs, would a 171 be too long? I am an aggressive rail skier, who throws in lots of spins and wutnot on rails, so I am concerned about the length and width of the TC? Im getting a pair of afterbangs to replace my punx as my urban/railjam/preseason ski. Which size would be more efficient the 166 or 171? I am also getting the Stepups for my comp season and for going to some massive parks out west, again 166 or 171? Thanks for your help and don't try to convince me otherwise about the skis Im getting +K to everyone!!