[Q] Need help with Bionic, that has Safestrap 3.6 installed but no OS topic

I work at a cell fix shop and one of my customers brought in a Bionic that his son tried to root and ended up with Safestrap 3.6 installed but no OS. I have done OS fixes by completely wiping the phone and re-installing the stock OS but I would like to just be able to place the stock os in the stock os rom slot but I have no idea how or where to start looking for those files and I have tried searching here for them but I don't know what the official os is for this phone. Any help would be awesome, until this happened I had never even seen safestrap, and I have no idea how to use it and not the time to figure it out by myself. Thanks guys!