P-Channel Mosfet Gate Drive Topology with 20V Vgss Protection?
You could use a low-side gate driver, give it a 
GND of -12V or whatever relative to the high rail (eg. LM7912) and then you only have to shift the input control voltage to it. 

You could do that easily with a few discrete parts or use a logic-output optoisolator. 



Reverse polarity protection is easily done with the classic Vin to series P-channel MOSFET and a resistor (gate to ground), plus a zener diode (gate to source) to protect the gate. You cannot make the other P-channel MOSFET do double-duty because of the body diode.