I don't think Rudy Giuliani would ever get involved in a case like this one. He might have been perfect for this years ago, but he is way past his prime and hasn't functioned in any capacity as a prosecutor in almost 25 years.
For all his flaws, Chris Christie might be better suited for something like this. He's younger, has never been afraid to offend anyone, and probably would have been the U.S. Attorney General if Mitt Romney had won in 2012.