Christina,
I've been in the Industry for a good number of years designing systems and I believe you can go with a good basic 8 camera package that will fit your needs quite well. Running the cameras back to the DVR on a standard RG59U cable is not "Rocket Science" to install with a little training on BNC connectors. If you've handled RJ45 connectors on a data network, then these should be a snap.
Low Light or Day Night cameras would e your best bet possibly with some IR illumination in outlying areas of the facility.
Feel free to contact me if you'd like to discuss applications.