John wants to get an uninterruptible power supply for his router. Leo says he'll want one that supports power conditioning. Leo has used APC UPS devices, Tripp Lite makes a good one, and a lot of people recommend CyberPower. The term to look for is "sinewave," which cleans up the power and would keep his gear safe.
If he wants to be able to reboot his router remotely, he could look into a remote smart power switch. That's a good idea as well. He could call into it, enter the password, and reset his router remotely.