Multiple earbud phones amplifier for recording a group of up to ten people at a time.

I want to record groups of people on an iPad through an iPad docking station[Focusrite iDock with a normal headphone jack plug]. The singers will all be recorded together on one mic but each one needs to use his/her own earbud headphones to hear his/herself and be able to adjust his/her individual volumes. The unit can be AC driven and it would be great if it could be attached, in some or other way, to the mic stand on which the mic is held through which the whole group is singing so that each one has access to his/her volume control