Depends
Hello, Just finished the two front seats and rear bench seat. I have the straight hog ring pliers (From JBG) and they are much better than standard pliers. I have not tried the angled, but can see some advantages when you are securing the foam to the seat frames. I would estimate that you need about 40-60 hog rings per front seat. That is about the same number I removed from the factory installed upholstry. Bench seat is about 10 for the back rest, only staples for the bottom part. Overall seats look very good, but I do not have the raised edges likes the original look. If you want that you must secure foam and upholstry close together (inner pocket, not outer pocket). My fabric came off ebay (can not find the name of seller, but he is out of Oregon) and it works very nice.
Good luck,
Burt