sorry I cannot recommend a UPS.
maybe an alternative entry is helpful: https://community.agilent.com/thread/1344-ups-and-gc-ms-yes-no
We acquired two Tripp-Lite Isobar surge protectors (Amazon). The design was intended for large, flat panel displays and high current home theater systems. They've been helpful in minimizing disturbances in the local power grid. We purchased them for two Tekmar 7000 headspace instruments which we are no longer using. We now use them on our autoinjectors and computers. They are not high (20A) current rated though, so they can't be used with the GCs. Good luck.