We had Frank Barker one year, but none of the others you have mentioned. We sometimes look outside the PCA. Two years ago we had Mark Earley, of Charles Colson's
Prison Fellowship International. Mark is a previous member of our church, former Atty General of VA (and gubernatorial candidate), and a personal friend. I'm not sure who we've got lined up for the next conference.
If you want to get ecumenical, Al Mohler at the Baptist seminary in Louisville is reformed. I left him off my first list.