Hi, E, and welcome. Looking forward to seeing you in Jacksonville.
I would think you could substitute the Miller books for the Famous Men books. The main challenge you will face is that the Miller books have many more chapters than the Famous Men, so you may need to double up on some of the readings. The other challenge will be fitting the Voices of the Renaissance and Reformation book to the Miller book’s chapters, since it was written to correspond to Famous Men of the R&R. But you can probably look in the Miller book’s index to see in which chapters the various men are mentioned and align the Voices collection accordingly.
Doable? Absolutely, with some tweaking. Hope this helps!