I guess the thing I am in part confused with a lot of suggestions is people are suggesting $400-700 POE switches. I am sure they'd do a great job, but the OP is looking for a gigabit backbone and 4-8 IP survelliance cameras. Unless you really need to go reproductive organs out on it, a 16 port gigabit dumb switch or semi-managed switch and 1 or 2 10/100 POE switches with 4POE/8 ports or a single port and adding injectors as needed should work very well.
At less than half the cost of many of the gigabit POE switch suggestions, yet probably not really add anything useful to the OP. POE gigabit tends to be significantly more expensive than 10/100 POE and is geared more towards supplying power for things like remote access points, or other switches that need to be POE powered. Not really things for like IP/survelliance cameras and other "basic" POE devices that likely aren't going to be doing more than 5-15Mbps.