Yes the receiver is the same. What determines rifle or pistol, is what the receiver was sold as.
That goes for the Encore, and G2, and Contender receivers also. The Pro Hunter is a Encore receiver, and will except any of the Encore barrels, pistol, or rifle. You don't have to stick with the more expensive Pro Hunter barrels
If you want to switch between rifle and pistol grips, barrels, and stocks, The receiver will have to be purchased as a pistol.
If purchased as a rifle you legally can't convert to pistol.