I have 27 cat6 points in total and some of them I intend to use
for telephone and some to transmit hdmi from media room to other room. At least 4 will be used for PoE to power wireless access points as well as ip cameras.
I highly recommend you to not mix IP cameras with you Data network you will have an extremely slow network, especially is they all connect to a switch instead of the DVR. Best will be your main home network under one switch and your IP camera system on its own switch if you want internet access to the DVR just connect it to your modem/router. But keep those cameras away from you main network.
As for the switches if you do want to run under one you're probably look at a switch with VLAN capabilities to be able to separate the traffic between networks, but will cost you a lot.