I switched from APC RS 1500VA to this:
Ideal is pure but I would not say it is a must essential. But I do like and have half a dozen now of Cyber units.
If you want to do the job properly, you need a UPS. Apple advise that for newer Mac Pros with the more efficient power supplies you need a "Pure Sine Wave" UPS. That means the Smart-UPS range from APC and the equivalent from CyberPower. It eliminates the cheaper APC Back-UPS range because they are "Stepped Sine Wave". For example, single-processor Mac Pro and 27" ACD draws about 27% load at idle on Smart-UPS SMT1000I and gives around 45 minutes of time on battery which is plenty for a while of "wait and see if it comes back on" followed by a controlled shut down. Surge protectors are only really intended to protect the device from over-voltage spikes on the power line which is why they are cheap. Those that offer battery time as well would struggle to handle the demands of a full desktop computer for more than a few seconds... a minute or so at best. Owners in rural areas may suffer worse mains supply than those in urban areas but the users in cities will be more likely to suffer from power sags and interference which can cause unwanted reboots. These faults will be poorly handled by the Surge Protectors. Ultimately the choice to get a UPS is up to you but I would not waste the money on a Surge Protector.
I have never seen a 1500VA provide a running Mac Pro, let alone monitor, for more than 20 minutes.
There are very long threads, old ones here, MacRumors tend to try to "stick" all comments on a subject like this in one place.
I live in rural and when there was flooding (far away but affected the state infastructure ) we had daily clitches. One lesson: be sure t o protect modems and routers and their coax and RJ45 as well.