We built a new house in 2007 and insulated the exterior basement walls with rigid styrofoam. We are finishing the basement and would like to insulate the interior walls also. We live in the upper Midwest, so our winters are very cold. We don't want any moisture issues that will cause mold or mildew. We've found information that advises against an interior vapor barrier of any kind, so the moisture can escape the poured concrete wall. What type of insulation should we use in the interior stud walls?