For wedding decorations, I would recommend A1 Party and Event Rental. I used them for my wedding about 3 years ago and I rented all of the chairs and linen from them.
There are a few rentals places in Columbia. A-1 Party has a good selection on wedding rentals. You might also try Lindsey's Rental and US Rentals. If you can venture out of the Columbia area, Celebratios in Kirksville is a good place to rent as well.
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