I did the exact thing for one of my bathrooms and it works great.
Few comments about this setup:
0. you need a 3 control setup (hot, cold, diverter)
1. Long levers will interfere with each other. Get a short handle lever or even better a round one;
2. Depending on the brand, you can have both showerheads operate at the same time and it is awesome!
3. If the space above your bathroom is an attic, make sure to insulate your pipe
The only minor draw back is that if you use the rainshower head, you need to put the diverter in the middle position to allow the pipe overhead to drain (or else, it will dump water in the middle of the night when you lease expect it)