Rudy Giuliani would be an excellent pick for, say, chief of staff in a Trump administration. While he would be a good selection for AG, his talents are much more organizational, as regards his service as New York City mayor.
Trey Gowdy is aggressive, principled, and seems to think on his feet very well. This is kind of in line with the prospective nominee sort of picking out his (or her) Cabinet beforehand, on the sly, of course, and vetting them thoroughly first. Then if the nomination and election are successful, announcing them to the world after the winner of the general election is declared, well in advance of assuming office in January 2017.
Hit the ground running.
Rudy definitely needs to be in there. I remember in the 2008 convention, Rudy was the only one who seemed willing to talk about who Obama really was, and he pulled no punches. He has warts, to be sure. But he is also someone who you want in your foxhole.
Gowdy never last a case as prosecutor, mind like a steel trap. He has p-poor conditions going against Washington cartel.