Well if you could possibly get your hands on 3Ds Max, you could use the render function, which gives prettier pictures.
Then what G-Max can show you in its work space.
IIRC, if you first import the body you want to use and then import the head, the head should "jump" to the correct place on top of the body.
Not sure I would have to do an experiment with that myself.
Anyway list of tools you'll need:
G-Max or 3Ds Max.
NWmax to import/export models.
KotorTool to extract the models and their textures.
MDLops to compile the models to the import format.
Most info about the 3D can be found here:
http://www.lucasforums.com/forumdisplay.php?f=595)
And I'll promote the SEARCH function( above at the right corner of the screen) to look for threads about importing and such.
You'll be delighted what SEARCH can do for you ;)