I'm using one of these:
http://www.amazon.com/CyberPower-CP1500PFCLCD-Compatible-1500VA-Tower/dp/B00429N19W (the 1500VA/900W one) and I'm really happy with it!
🙂 Had several power outages and absolutely no problems - switched to battery and back. I observed once, while doing a 24 hour prime95 testing that there were 4 outages (short time) in total (it's recording the events) and got no errors at all! :cool:
They have built in power meter and have a software to connect with your pc - you can check how much power your system is actually using. :cool: Oh, and turn off the alarm! - if you have an outage at the night, it will scare the sh** out of you...