Most OEMS use PPG paints. General Motors, for example, use PPG paints exclusively. I lean towards PPG just because I have seen firsthand at my plant their technology, years of experience and quality of the paint. We tried a trial of Dupont paint once and it was subpar so it was not adopted.
However - for a simple bumper repair, I am sure any name brand paint would do you well...but if the price is not much more, go PPG. They take a lot of time to make all their products compatible with each other. Their primer, base and clear are all designed to work together so be sure the Bodyshop is using all PPG products. Likewise for the S/W since they probably match their products too.