ukrain

I just purchased a Benelli super nova In edmonton alberta canada and I am interested in purchasing 2 things for it. 1 is the ghost sights that I have seen for it and 2 is a pistol grip stock. I have went to cabelas where I got it and they have no accessories for it. Could some one please help me out as to where I can find these Items for it. Also Im not really understanding on how the ghost sights mount to it, There are no pre drilled and tapped holes. ?