I suggest building your own UPS with strictly DC outputs. Most of what you'll be plugging in runs on DC anyway. This does mean you'll need to dig into some of your equipment to find the DC access point, but on other equipment you'll only need to cut the wall wart off the end of the cord.

You can choose your own battery and battery maintenance equipment for maximum longevity, and choose your own switched power supply with different tap points for different DC voltages.

This is simpler and more reliable than AC line-interactive UPSes because synchronizing an inverter with wall-socket power is not required. Yes, you need some EE skills to build it, but the end result will be far more reliable than a cheap off-the-shelf UPS.