Got the 3FHL catalog working - had a little trouble at first when I tried to use the .fit file, but eventually got it to work with the xml file.
Continued to work on trying to find the FGES catalog, I can't find a single file for the FGES catalog. I found a paper about it, and I may have found a set of xml files which each contail the model for one source. I am starting to think I may have to just combine those files myself, there may not be an already combined file.