With the AEW12 you can have two separate mixes by running one aux to left and another to right (or any audio sources of course)

then move the switch on the back of the transmitter to mix..this will make your body pack panning turn into to separate volume of those
individual channels.

So technically you could by a AEW12 wireless system and then an extra body pack and run two mixes

The best way to get a true stereo individual mix is to buy an AEW12 unit for yourself of course.