you could try to connect both Movie File in TOPs to a Switch TOP, and set the Switch TOP to blend between inputs.
connect each of your movie file in TOP to an info CHOP by dragging and dropping the movie file in TOP onto the info CHOP.
set the info CHOPs scope to index fraction, that will tell you when your movie file is ended or about to end.
To get your movie to replay when the other movie is ended you will need something like a CHOP Execute connected to each of your info CHOP and a python script like:
if val > 0.95:
change the script to your like and set it up in a way that when your first movie file ends it will trigger the second movie file, and viceversa.
and lastly you will need a way to move the switchTOP index from 0 to 1 in a graceful way when your active movie is ended or about to end, maybe using a trigger CHOP for example, or a simple 0 to 1 smoothed with a filter CHOP or lag CHOP.
hope that helps