The Menno-hof museum is good for learning about the religious culture of the area. For fabric, Lolly's downtown and Yoder's dept store plus about 10 miles south of Shipshewana is Zinck's Fabrics in Ligonier - prices can't be beat!
If you are going on Oct 2, the flea market is open all week, usually only open on Tuesday and Wednesdays.
We are camping in Shipshe that weekend. I can't wait!