If you want Fake Out, go with Technician Ambipom. It will pack a punch along with STAB. It has U-Turn and a good speed, so it can act as a scout as well. After dealing damage with Fake Out, it can U-Turn out and switch to something else.
I've also seen Ambipom with only Fake Out and Last Resort, which is seriously annoying (and a bit gimmicky), especially if you don't have a ghost type on your team.
I prefer to use Mienshao as a Scarf Pokemon, so Fake Out is useless for it.
In any case:
Item: Life Orb
EVs: 252 Atk, 252 Speed, 4 HP
Shadow Claw/ Pursuit