Lawyer Required to Represent our Business

We need a lawyer within United States to represent our Chicago based business against an expected lawsuit from a vendor who is trying to stop us from selling their products online whereas we don't own those ebay/amazon accounts and we are not the actual seller but just fulfilling the orders for our customers. We work like a fulfillment center and do pick, pack and ship the products and we need to defend our case as we not going to stop our business and want to take it to the end with them. Thanks Sunny