Good Morning –
I have two suggestions, Norcostco is a large Scenic and Costume Company out of Minneapolis, MN https://www.norcostco.com/drapery.aspx. My other suggestion is, contact the Technical Director at the Repertory Theatre of St. Louis http://www.repstl.org/about/staff. She should have a suggestion or two of a company that might be more local for you.
Good Luck with your project.