You should be able to use the omni with the Prism Rocket AC. Dual sma connectors. You can not use this with the nanobeam m, and would have to upgrade all radios to Nano/litebeam AC. Do not use the nanobeam-16. Use the nanobeam-19 (I have had many problems with the 16s). Be sure to use shielded cable and shielded connectors.
I use both and find that Rocket M with NSM5 Nanostations work great for most camera applications. The dual NICs come in handy for dual cameras and POE passthrough to repeater radios. Usually get over 50 Mbps per radio. Have you optimized your camera settings for efficient bandwidth/low noise operation? Is signal level at rocket and client where upgrade needed better than -55 to -60. Have you done frequency analysis through the rocket and nano to verify no excessive interference? If any of the other 3 radios is operating in the weeds or with excessive interference at the client site, this can bring down performance of the whole network. Consider changing frequency and/or changing such radios to higher gain/narrower beam design.
You must have quite a few cameras at that site for AC. You can also upgrade to 2xnanobeam ac for a point to point just to that site if it needs quite a bit more bandwidth rather than replacing all the camera site radios.
Ubiquiti actually does not promote omni application (sector only) probably due to local interference. I have no problem using omnis as long as in a rural area or with areas not prone to interference.