What is the best 16 camera CCTV surveillance system?

A customer recently contacted CCTV Camera Pros with the following questions to help decide on the best 16 camera CCTV surveillance system for his requirements.
1. About the PRO-680DN Box Security Camera, 1/3" Sony Effio EXview HAD CCD, 680 TVL: What is the differences between the different lens offered with this camera?
  The different lens options offer varying ranges in the size of the fields of view that they support. The larger the lens size, the more narrow and zoomed in the field of view is. For example, a varifocal lens adjusted to the 50mm setting will capture an image approximately 2 feet horizontal at 25 feet away. A 2.8mm setting will capture an image approximately 70 feet horizontal at the same distance. These examples are using the same PRO-680DN box camera (just different lenses).
  
  You can use the CCTV lens chart on this page as a reference for more lens size examples:
  
  https://www.cctvcamerapros.com/Security-Camera-Lens-s/42.htm#lens-chart
Since this camera is not infra-red, can it sees in the complete dark?
The PRO-680DN can see in very low light but is not designed for ultra low light or zero light surveillance applications.

For zero light, we highly recommend an infrared CCTV camera such as one of these models which are already in an outdoor weatherproof housings:

https://www.cctvcamerapros.com/Outdoor-CCTV-Camera-p/bipro-s600vf12.htm

https://www.cctvcamerapros.com/Night-Vision-CCTV-Camera-p/bipro-s700vf50.htm

https://www.cctvcamerapros.com/Vandal-Dome-Camera-p/dpro-as700.htm

What is the difference between the SYSPRO-16P1609 package and the SYSPRO-16P1606A package? I see they have the same cameras.
The only difference between those two surveillance systems is the DVR that is included. The 16P1609 uses our iDVR-PRO16 while the 16P1606A includes the iDVR-E16 model. You can view the specs of each model here:

https://www.cctvcamerapros.com/16ch-H264-DVR-p/idvr-e16.htm

https://www.cctvcamerapros.com/CCTV-Camera-DVR-p/idvr-pro16.htm

The main differences is that the iDVR-E16 can only go up to 2TB in video storage while the iDVR-PRO16 can go up to 6TB. Also, the E series iDVRs includes the best mobile applications for iPhone, iPad, and Android. If mobile access is important to you, I recommend the iDVR-E16. If you need additional storage, you can upgrade to the iDVR-RT16 which uses the same mobile apps as the iDVR-E16.

https://www.cctvcamerapros.com/16-Channel-D1-Real-Time-DVR-p/idvr-rt16.htm

More information, camera viewing screenshots, and demo videos of the iDVR-E series and RT can be found here:

https://www.cctvcamerapros.com/Internet-Video-Surveillance-DVR-s/424.htm

The iDVR-PRO info can be found here:

https://www.cctvcamerapros.com/CCTV-DVR-MAC-Viewer-s/403.htm

What is the maximum distance between one camera and the DVR? I mean for the cable?
RG59 coax cable is rated at 700 feet, however if you need to run the coax cable this far, you need to supply power to the camera closer to the camera because running low voltage power at that distance is a problem. If you need to run the coax cable further, you can use a video amplifier to boost the signal.

https://www.cctvcamerapros.com/BNC-Amp-CCTV-Splitter-s/419.htm

Does the PRO-680DN Box Security Camera, 1/3" Sony Effio EXview HAD CCD, 680 TVL can ZOOM, and move from left to right, up and down. Or is it FIXED?
This is a fixed camera. You can find PTZ cameras that can pan, tilt, and zoom here:

https://www.cctvcamerapros.com/PTZ-Security-Cameras-s/45.htm

What is the maximum viewing distance for the PRO-680DN Box Security Camera, 1/3" Sony Effio EXview HAD CCD, 680 TVL in the DAYLIGHT and in very LOW LIGHT conditions?
Please refer the lens chart in the link below. Remember that is your areas are ultra low light or no light, you should either add lighting or use infrared cameras.

https://www.cctvcamerapros.com/Security-Camera-Lens-s/42.htm#lens-chart

What is your best IR camera? (I mean the one that can REALLY SEE IN THE DARK). And what is the maximum viewing distance in the DARK?
I highly recommend each of these model IR CCTV cameras. The lens size and IR viewing distance is on each page. These are some of the best IR CCTV cameras.

https://www.cctvcamerapros.com/Outdoor-CCTV-Camera-p/bipro-s600vf12.htm

https://www.cctvcamerapros.com/Night-Vision-CCTV-Camera-p/bipro-s700vf50.htm

https://www.cctvcamerapros.com/Vandal-Dome-Camera-p/dpro-as700.htm

About HBPRO-601HB Outdoor CCTV Camera Housing, Built in Heater/Blower, 24VAC, since the power supply box (PSPRO-DC18 18 Channel Surveillance Camera Power Supply Box, 12 VDC) coming with the 16 cameras package supply only 12VDC, how can it be powered?
These individual power supplies are typically used with the heather blower housings and because the PRO680DN is a dual voltage camera, you can use the same power supply to power both the housing and the camera. You just run a small jumper cable to run power between the housing power terminals and the camera power terminals.

https://www.cctvcamerapros.com/Heater-Blower-Power-Supply-p/pspro-24vac50.htm

Here is the version of the camera housing that does not have a heater element and fan:

https://www.cctvcamerapros.com/CCTV-Camera-Housing-p/hpro-605.htm

Can I remove the heating element and keep only the blower?
This is not necessary as we offer the above CCTV camera housing with no heater / blower.