It would be fairly easy to make a CF copy of the Phantom shell. If done properly, it could be lighter weight and stiffer. Stiffness is not always a good thing. It would likely break in a crash where the flexible plastic would have survived. It might also transmit vibrations from the motors that would be absorbed by a more flexible plastic shell.
Any antennas would need to be outside of the shell for good reception, including receiver, FPV transmitter and GPS.