Need Ups for my pc

Hello everyone,
I have the following configuration
CPU- AMD Phenom X4 955be
GPU - AMD 6850
CPU cooler CM hyper TX3 EVO
WD 250 GB hdd
logitech X 540 speakers
Benq 22 inch LCD
corsair 4 GD DDR3 RAM
Mobo- Asus M4A88T-MLE
PSU - gigabyte 460 watt.
I want a UPS which can handle voltage fluctuations.Budget is 2-3 k (little bit flexible). Backup time is not something i am looking for but i don't want any unexpected restart or shutdown. Please suggest a good UPS. Thanks in advance.