Your TV & AV Receiver alone will chew up a lot of the battery power on that UPS. If all you are wanting it for, is to allow the DVR to stay up during short power outages, I would just hook that alone to the Battery side. All the rest of the equipment can go to the Surge Protection only side.
Now keep in mind that if you do not have the Power Inserter on a UPS, the DVR will not do anything during a power outage, if it is in the middle of a recording and the lights go out.
The only gear I have on a UPS is my networking stuff down in the basement. Only my NAS & Gateway for ATT U-Verse is on the battery. Everything else is Surge protection only. Once we go into a power outage, I shut down the NAS and just leave the RG up, so that we still have some Internet connectivity for a while, until power comes back up, which is at most two hours.
I could care less about needing the tv, dvr, av equipment during a power outage. My main concern is to be able to still check Noaa.gov for weather information, if the cell towers go down, and we cannot use the cellular connection.
Now if you have a Generator, and want everything to stay online, until you get the generator up and running, you need a good sized battery backup to run your A/V center. They make whole house units, that you can attach multiple Deep Cycle batteries on, to allow time for the generator to come up online during a power outage event. The gear in the house would never notice what happened, and the UPS would help iron out any problems while the generator is running.