Quilt Block in Valley Junction (original name of the city of West Des Moines and the name used for the old downtown area of WDM). Creekside Quilting in Clive (another suburb of Des Moines). Ankeny (north of DM a few miles) also has a quilt shop. Ames, Adel, and Grinnell (a little ways away from DM) all have quilt shops. (Grinnell is the city quilt designer Judy Martin calls home.) Winterset, not too far from DM, is home to Fons and Porter and their quilt shop. Indianola, another nearby town, also has a quilt shop.
Unfortunately, you are a month too late for the AQS show in Des Moines. It was wonderful!