Let me say this, when I started my time at a bible college, I wanted to be the next Billy Graham. I thought I would be the perfect man to fill his shoes. I would love to preach to thousands at a time and impact countless lives for Christ. It's a noble dream, one many Christians should pray for others if it's not ultimately God's will for their life. However, we must keep one thing in mind. God calls us to be who we are, not any one else. We are to be Christ like not Graham like, Driscoll like or any other person God has used to grow His church.
This is not said to discourage you, but to suggest that you pray for God's prespective on your life to be clear and that you would be content to serve him in any way He decides to use you. He might meet you at you desires, or He might tell you to foollow him a completely different dicrection. Our part is to be willing to do whatever it is God would call us to do. The more I prayed over my dream, the more I wanted the fame or the respect the great Christians have gotten over time. Now, I see that God will use me as he sees fit and that will be better than anything I could have dreamed.
Now, with this said, it appears that you would like to teach the word of God to others in this world. So, a degree in apologetics or just general theology would be practical for your ambitions. Again though, ultimately, God's calling must be the one we cling to.