That's a pretty decent rig, but the trouble is that the power supply won't let you upgrade the graphics card much, and the graphics card itself is considerably worse. There are a few other points that I would nit-pick, but that's beside the point.
So, I have a question, then. What if you went with a good base system with a lower-end graphics card and saved up to upgrade it? That would be your best way to get what you're looking for.