XSI Mod Tool (look for the free version), 3ds Max cannonfodder
This option uses the smd file format, which fully supports bone assignments, thus you can add new points to your mesh and delete points. It supports editing the mesh using either Modtool (free) or 3ds Max. This tool does not support the fit/fat/preg morph, so your meshes will stay the same if the sim is fit or fat.
The original normals are not maintained with modtool edits of the smd file, and you might need to add a few extra points to your mesh if there are spots that will not smooth correctly. You must also weld boundaries (or filter points) to smooth over the mesh’s seams.