16 Channel Surveillance DVR Systems
Some 16 channel video surveillance systems can support up to 32 cameras. So, depending what your current needs are, what you anticipate for the future, you might consider this category of security equipment. It is standard to have picture contrast controls, adjustable frame rate, and date, date and time recording.
At this level, you probably want screen splits so that you can view more than one camera input at a time. Screens that split into 9 and 16 sections are popular at this level. With the 16 channel system, it may be that you will want different types of cameras for indoor or outside.
When looking at bundles or individual parts on eBay, check out the return options offered and the sellers rating and feedbacks. But you might also consider features such as remote viewing, record compression, and playback while recording.