New to Linux

Just getting interested in Linux as a desktop option and getting a new desktop as well. I have ordered the latest Kubuntu through ShipIt and was wondering what kinds of hardware others are using it on. I (unfortunately) don't have nearly as much time as I would like to devote to tweaking the hardware, so was thinking of just going with a low cost solution something from Dell with pre-installed Ubuntu, or maybe even Zareason.com. Also I am wondering if anyone has test-driven the really cheap offering from Sears ($198 after rebate) I might consider it if it isn't too bad. Thanks!