All, I'm having a party in a barn that has no wifi or cell service. I have some good quality free standing speakers and also an iPhone 7 (no audio jack). I'd like to use the iPhone as a music source and also use the speakers I have (four preferably but could just use two) to play a playlist from the iPhone. To note, the speakers are not wireless. My question, what is the best option to make this happen? I'd like the best sound quality as possible. I'll also need to be charging the phone at the same time so the battery doesn't run out. Thanks very much.