Do you recommend any specific UPS units or any specific battery powered pieces of equipment?
For a UPS, make sure you get one that automatically switches over and has atleast some outlets that are not used for it and some are (to allow for some heavy items like lights or non-essential filters) to be turned off. I try to find one with a decent warranty and one that lasts atleast a good amount of time with the load you expect (look at the items to see wattage per hour of usage), and then see how long that will go. You could also get one with a digital display that outputs how much load is on there and will tell you how long it will last.
You ideally want one that lasts at a bare minimum of 4-6 hours, or ideally 8-12 hours. Anything more than that is an added bonus, especially those that have replaceable batteries since you can have a pair as a real backup.
REMEMBER; they are pricey, but you are getting a power backup AND a surge protector (a really good one at that).
For a battery backup; you really just want air pumps/bubblers that can mix up the water a given rate. I just try to find one with common batteries (ex: AA or AAA) since others take small 9V batteries which always seem to last longer and cost more money if you buy the batteries in bulk.