00tour, i highly doubt you will need a new piant job. If they can't match the bumper perfectly, then they will just paint the rear quater panels and use them to do the blending, but i highly doubt they will repaint the whole car!
As for my accident, they will probably try to fix the bumper, but will replace it if they have too. IF they can fix it, I will have the advantage of better a better matching bumper....or it will be easier to match. We'll see