That looks like a balanced build to me.
As I may have said in previous posts, I'm not too familiar with minor details in fine tuning performance, so someone more savvy might have a say for the memory etc. However, in a build of this level a notch this or that way would only be noticed in benchmark programs, not in games or everyday performance.
You don't say anything about your hard disk choice or, what's most important, the power supply. Are you going to salvage them from your current computer? If so, are they new and good enough to be considered reliable?