Trying to make Shadow Elemental Lightning Arrow

Hey im new to the game trying to make elemental lightning arrow
http://www.pathofexile.com/passive-skill-tree/AAAAAgYAE54eGipbjDa0ONIZ1tHed-UZ-_X_kw==
this is my current build tree am i going the right way for elemental lightning arrow? thoughts please

drop spell damage and elemental damage and go for arcing blows

http://www.pathofexile.com/passive-skill-tree/AAAAAgYBE54eGipbjDbSGdbR_5O1SG17VUsmlaSR