AVANZ,

Quote - ... morphing a character, especially across seams is a bit of a challenge for me.

I don't know much about modelling, but I know that if you can keep the groups intact through an import and export from your modelling app, you can morph the full body obj, then use "Pozers little Helper" (PLH) to make INJ and REM files from the full obj. That way you don't need worry about seams. PLH needs a bit of setting up the first time you use it, and has a bit of a learning curve. It's not the most intuitive app to come to grips with, but once you understand how it works, it's quick and easy enough to use, and it's free.