Can you give anymore details on number of people you have invited, budget range, etc?
There are a lot of locations around the area but they vary in price, size, and food.
Some of the more mid range facilities (i think, I don't know exact pricing)
Traditions in Eldridge
RI Arsenal Golf Club House
RI Arsenal Heritage Hall
Black Hawk State Park Lodge
Milan Community Center
Eldridge Community Center
The Quad City Botantical Center is beautiful anytime of year and very reasonably priced.
Click on each tool to see a sample.