Mixed Sharpedo :O
Smogon runs 148 Atk / 252 SpA / 108 Spe on a Speed Boost mixed Sharpedo set. But that's Speed Boost. Since you're running more physically based moveset, you could probably switch the Atk/SpA of the previous EVs around/. Or run a 252 Atk/4 SpA/ 252 Spe set :P maxmising speed / attack (main offense) and dumping the rest on SpA, since Hydro Pump is strong enough anyway. xD