1. Considering the video quailty your church at least need HD1080P resolution camera, which super than SD video, 4K PTZ Camera image quality is good, but price still at the high side, not so cost-effective,so the HD PTZ Video Cameras is the best choice.
2.The Optical Zoom have 12X,20X or 30X, how to choose? Depands on your budget and your church space, 30X optical zoom camera can capture a head and shoulders view of a pastor from 75 feet away.While a 20X optical zoom camera can zoom 50 feet away. If subjects are closer than 25-50 feet you only need a 12X optical zoom camera.
3.Signol quality,there have 4 types of signal they are called NDI, SDI, HDMI, and USB.Which one you need? Depends on the device you connect and the distance you need to stream.HDMI cables can travel up to 50 feet without extenders. SDI can send signals up to 1000 feet without any signal loss. USB is the most limited connection losing signal after just a few feet. Network cables for IP connections can reach up to 328 feet or 100 meters.
So the SDI PTZ Camera WIN-M57S with 20x optical zoom which port is SDI, HDMI, IP is really the best choice for your Church.