Question Advice needed on UPS purchase

[Drone4four]

Greetings!

My new home and local neighborhood has been expericing brown outs every few weeks. The power for my whole home will flicker off /on for a few seconds. It's not a big deal but the fleetingly temporary brown out is enough to power cycle my Linux PC and interrupt my workflow So in the interests of best practices I figure getting a battery-surge protector combo would be a good investment.

• Here is my PSU model: GIGABYTE GP-P650B "650 Watts" 80 PLUS Bronze Certified Power Supply (GP-P650B)
• I have an LG "38WK95C-W" monitor ("60 Watts") . Full specs: https://www.lg.com/ca_en/monitors/ultrawide/38wk95c-w/
• Not sure about my modem

I believe those are the only 3 electrical devices that require protection.

I am considering these two Uninterruptable Power Supply Systems:

• CyberPower CP1500AVRLCD3 Intelligent LCD UPS System, 1500VA/900W, 12 Outlets, 2 USB Ports, AVR, Mini Tower, Black
• Amazon Basics Line-Interactive UPS 1500VA 900 Watt Surge Protector Battery Power Backup, 10 Outlets - Black

Here are my questions:

1. They are both 900 Watts. That is greater than my power requirements. But the only other options I could see on Amazon were 600 Watts which is less than my PC PSU.
2. What does "1500VA" mean? That seems to be an important characteristic of these UPS Systems and I am not sure where my hardware fits in with this requirement
3. The first one says it should last "8 hours" which leads me to think this is wayyyy overkill becasue my power goes out for just a few seconds. I don't need a battery to last for hours.
4. What other factors would you people suggest I consider?

 

[Drone4four]

To correct myself, there is a chart comparing different UPS characteristics. It says charge = 8 hours. But "Run Time" ranges from 10-12 minutes. Is that really how long to expect the full charge to last?

 

[Corwin65]

UPS is there to allow you to save and power down.