I am currently using 2 of the Lorex systems. The NVR 8ch HD IP system. I personally wouldn't install anything that requires a separate power supply and most budget camera systems require that. I went with cameras that are POE or power over Ethernet. This allowed me to make one long run of cat 5 cable to a POE switch and have that on a battery back up. Then I branch 4 cameras from there and the other 4 are powered right off the NVR box. With both on battery back ups and my router I am able to monitor remotely even if power is lost. It is more expensive then what you are looking at and a 16ch version will be well over 2 grand, but my opinion is do it right the 1st time.
I agree with the above poster about wireless cameras. Don't use them. They are great to keep an eye on the kids, but are not real security systems. Are you going to spend $100 on a battery back up for each wireless camera? If so you could have just bought a nicer system.
MM