I have a XION case, which is pretty snazzy looking and comes with a 450 watt power supply. Now, getting a case with a power supply included isn't the best idea, but it seems that this case has either terrible reviews about the power supply or really good ones. I can't quite seem to figure it out. However, I've heard a lot of people talk about the Raidmax Sagitta, which apparently has a nice power supply and it is VERY cool looking (and it is only about 80 bucks, my XION case was 60).
I like your system but you want to upgrade the video card from the 6600 series. I'm lovin' the processor though
. Just wait till you overclock that thing, it is beastly! Check the signature