Wouldn't a inverter be a better option than a UPS?
Especially if you would like to add heating pads etc? I'm not to clued up about the UPS models but from my experience the beeping sound drives me insane, i have found stand alone inverters with build in batteries and a charger if you're looking for a minimal setup @ 1200W for around 1500 if memory serves me right the downfall of other style inverters especially in a humid room is the acid build up it forms but then again you could even have the batteries in another room and run the cables to the inverter... and if you're demand for more power u can just add a battery... just my thoughts
Like the ceramic pot idea though!!