the rear window trim is the same for all g-bodies, but your car won't have provisions to locate the clips that hold the rear window trim in place, so you will have to come up with some other way to secure the window trim.
the quarter windows are specific to the GP. However, you can reuse your existing ones. The only difference between the vinyl roof windows and the metal roof windows was that the metal roof cars had a different gasket on them that extended over the quarter panel, giving the window a more flush look. If you install the vinyl roof windows without the vinyl top they seal fine, but there is a small gap between the chrome window trim and the sheetmetal.
Also, at least on my 83, the joints between the roof sheetmetal and quarter panel were unfinished beneath the vinyl roof, so you'll have some body work to do there.