I looked at the files for the offline character builder (offcb) and was not able to find any files for the Ultramodern, or Amethyst sourcebooks (both by DEM).
The offcb is very capable and from looking at my Amethyst book it looks like this would be a straight port into the offcb files. I don't have Ultramodern so I can say for that one, but DEM was very good about making stuff that was truly compatible. So I'd suspect it's also a straight port.
Manipulating xml is probably not the easiest thing in the world, but at least it is human readable. I would start small. Maybe add a few pieces of equipment to begin with. Then go to adding a feat or two. Powers are tied to classes so they are a bit more tricky, and classes require a bit more thought. It is all doable, but it is not quick.