To the OP. I have been shooting shotguns for over 30 years. I have yet to need a pistol grip on any of them. But it is your gun so do with it what you wish. I would heed the advice of just getting something along the lines of a Maverick 88 or Pardner pump which you can get in the security models for fairly cheap.
Best of luck to you in whatever you end up doing.
What on god's green earth do you think your doing?