Why do you think you need a UPS? A computer power supply is designed to handle the power straight out of the wall, and in most of the US that is a fairly clean signal and the filters on the PSU clean up the noise.
A UPS is only useful if you cant risk your machine losing power, have power outages often, live somewhere with really dirty power. In general a decent power strip with a surge suppressor is more than sufficient protection for the system.
Alright. That's sort of what I thought, but I saw so much about UPS's and the like...oh well. Thanks for the help!