I think that the Story of Christianity, Vols. 1 & 2 by Justo L. González would be an excellent addition to Logos. I have read these two books in the past, and am having to read them again for a Church History course that I am currently taking. These two books provide a very nice introduction to the history of Christianity, and even though these would come out to late to benefit me for my course, I would definitely buy them for Logos if and when they ever do come out.
EDIT: Found out that the auto-correct kicked in to change Justo to Gusto.