Serving Members, Growing Business, Shaping Communities. The Chamber originated in 1963 and serves the five communities of Surprise, Sun City, Sun City West, El Mirage and Youngtown. We represent about 700 businesses and 3500 professionals who have joined together to maximize their business opportunities. We are one of the largest chambers of commerce in the Phoenix metropolitan area and offer the following advantages to help you keep up in the fast pace and every-changing world of business. Take advantage of these benefits.