Will a 900VA UPS run well on a 550w PSU?

[secen]

I was thinking of buying an APC Power-Saving Back-UPS Pro 900 UPS
I don't know if it will work or not
specs:
http://pcpartpicker.com/p/ntDFpg
I also use a Bravia kdl 32ex720 TV, a mouse and a keyboard.

 

[RealBeast]

It will work fine, just install the PowerChute software and use the USB to UPS cable that comes with the UPS so that it can auto shutdown your computer at the time that you select in the software.

edit: forgot to mention, once you install PowerChute software it will give you an estimate of how long the battery will run at your current power use level, which is helpful IMO.