Camera for live streaming church services

[Meridivs]

We are trying to built a video-system for streaming church services over the Internet. What we have now is:
- a Blackmagic ATEM TVS video-mixer
- a Blackmagic IntensityPro capture card
- an i7 Dell Optiplex with 8 GB of RAM and Windows 7 x64
- two Cannon Legria HF R48 camcorders that will be filming at short distance without zoom

We are looking for a primary camera that would be filming from the back - 40-50m away from the scene - in low/difficult light setup

Question is what camera would fit this role best?

We are considering a Panasonic HC-X920 but wondering if an older DV camera like the Sony VX2100E could do a better job?

[Meridivs]

After digging some more on the Internet we narrowed it down to these three options:
- Sony HVR-HD1000U, entry-level professional camcorder with HD capability
- Panasonic HC-X920, remarkable sensor specifications (1/2.3" 3 backlit sensors, min. lux performance)
- Canon Legria HF G25 / Cannon Vixia HF G20, top of the line in online reviews, smaller sensor than Panasonic's

Giving the tasks at hand what would you pick?