This is a very old post that I have sense forgotten about lol I don't go on the rpf anymore really but I DID finish this costume and sold it after wearing. There's pep files for a woman suit that you could use which is the easiest way. Look up pepper Potts pep files and you should find it.
Custom ones take a lot longer to figure out unless you know how to make 3D models and convert them to pep files.