You picked a socket 775 design, but I'll give this another shot with the processor.
What is the absolute highest you will go on a processor?
Also, I'm trusting intel for my computer, so Garrett don't jinx it. The Q9450 better hold up, and it seems stable, and the reviews are good. (My bro has his up and running, rarely goes over 25% CPU load even with Crysis running.)