Doesnt your UPS have Nema R15 outlets on it? I have a HT/HiFi double conversion UPS and am a qualified sparky. Fire away.

The best bang for buck bulletproof UPS I found that could handle all I needed was a 20A cyberpower unit. It is layered in drywall dust, insulation dust, sawdust and just plain old dust. Quite the tank. It seems happy to be abused.... Lol.