Brian,
IrishEKU, over in the Kentuckiana forum, has found a guy that will do banners. You may want to check out his thread.
desert_racer,
See if your man can do gommeted banners as well. Irish is going to get a quote from a guy on 3'x5's with or without grommets. Also, make sure the guy understands that there will be several different screens desired. I'm bettin the sum of flags and banners for individual chapters won't be that great, but the total would be a good order.