There are also two talks that Rev. Alexander gave at the 2003 Shepherd’s Conference. The first message was out of 1 Timothy 4:16, and the second was from Ezra 7. You have to sign up to download them, but the good thing is that sign up is free. There are also quite a few other excellent free audio tracks there. You can find the Shepherd’s Conference page here.
You can also purchase two lectures on preaching that Rev. Alexander delivered at Westminster Theological Seminary here.