The Faiths of the Founding Fathers
For "The Faiths of the Founding Fathers," we would look at the various religious beliefs of America's Founders, including John Adams, Benjamin Franklin, Thomas Jefferson, George Washington, and John Witherspoon. I would be somewhat familiar with most of the material in designing this course.
The last option would be the most difficult for me: a course on World Christianity. But, it could be the most appealing to students, given the current interest in that topic. I see lots of faculty job ads for specialists on World Christianity and so it may be a good idea to add a course like this on the cv.
Let me know what you think.