Appalachian Wireless, GCI, Matanuska Telephone Association, and Celcom have all announced plans to sell Apple’s iPhone 4/4S. The four regional carriers join Alaska Communications and nTelos, which announced similar plans earlier this week. All the regional network operators will be offering the iPhones at a $50 discount compared to what the larger national carriers are charging. The devices will go on sale April 20. Plan pricing varies by carrier.