Offers great control of volume and easy set up. Sounds like you have enough singers. Encourage them and seek God's unity among them. On sound needs. An open air gathering would be difficult and rarely occurs here for live worship.
Weather is too unpredictable.
You will also need to distribute speakers throughout the crowd or down the sides of the worship area. I will let our sound engineer talk about equipment. Give us more detail on what you have today. I can mail you a cassette tape with music we have found useful. I can also mail you our two recordings.