You could arrange everyone to line up to form an isle for you to walk down – save the chairs for the older guests. Could they not supply benches instead that way everyone could have a seat? I’m guessing that if you are Christians you will be having a full service which could be quite lengthy? You could have a radio but how about someone from your church perhaps playing the violin or acoustic guitar? Remember, it’s your wedding and it is unique to you. It doesn’t have to be the same as others, just the way you both want it to be.
Good Luck
