I am familiar with Ragbrai which is more of a social event and even though your thinking 15,000 Crocke has a very good point. You should scale your number way back and plan on serving up 50 to 100. Think about doing it for fun and as an experience for next year. If things go well you'll sell out and run to the store for brats - if things go slow you wont be out all the money to feed 1000 eitherway you will have had fun and you'll be better prepared for the next big event like the College World Series in Omaha June 19th.
Weber Kettle 22.5, Smokin Joe, Treager jr, 18.5 Big Green Egg "Think outside the egg" , and a brand new 1965 Kenmore Barbecue Grill no.2626 "Barbecuing is fun with a Barbecue Grill"
on the World Wide Spider Web at Mojobricks