Whole bumper might cost you more, but is easier to just deal with the bolts/clips that go through the fenders and the 4 large bolts that hold the bumper on.
The small bolts along the bottom edge of the bumper cover are usually rusted (depending on you demographic).
Keep in mind, from my experience, the bumper on a '88 I had was three pieces (main front, small section on each fender) in the front and back. The two '90 models I've had have one piece bumpers, nicer looking. There are also flat black rubber bumpers on the base models which some will claim are not paintable, but I've found professional auto paint and cheap spray paint will stick if preped right.