Nice idea, but I think the effect is diminished by the viewer being able to tell that some pairs of arms actually belong to the same person whose body is off-camera. Perhaps get more people involved, so everyone contributes only one arm to the scene.
I don't know about the location but I think you should do something different with the arms! Like, let them be separated, every arm is some kind of distant from the other so that they don't look like there is just some person waving with both hands from behind the camera. I hope you got what I meant (: Good luck!