Well, it should be pretty straight forward to set up the main router / gateway. You can either use the 'wizards' within pfSense or do it all manually. If not certain on 'how to' there are some ok videos on YouTube, and some are not so ok.
I've installed SNORT, and initially I added in squid and squidguard, but I have moved those to a separate machine due to a bit too much load with those packages, since my hardware ain't on the 'high end' of things. I have 5 NIC's, where I use 3 actively now (WAN, LAN, WLAN), but have reserved one NIC for future extra WAN and one for a GUEST network. The basis of pfSense setup should not be to complicated.
The part it could be hardest to find documentation for is how to separate the traffic between the WAN interfaces if the amount of videosites involved are many. Routing on the Application layer might be the answer, but I've haven't tried this in practical terms since where I live the options for multiple WAN's is not there (yet). I've considered using a 4G router, but since the subscriptions are still bound to number of GB traffic it hasn't really been an alternative, especially not for video.
Not sure if it was much help, but I found the base setup for pfSense to be pretty straight forward. I used the wizards to make the standard install, and modified the setup later. The load balancing / routing on the WAN is something I have not tried (yet), but I do hope to get there one day as well. All of this is at my home, and I do have some bandwidth / traffic 'hungry' users @ home…
Knottolf