Upgrade advice

Hi all,I wonder if you could help me. It is time for me to upgrade my PC in the next few months. And I want a PC that will do FSX justice. I had to shelf it as the frame rate on my old PC were, to say the least, a bit on the low side!!I prefer commercial flying and using add-ons such as Precision's 747 and Level's 767. So does anyone have a rig specification that will run FSX in the low 20fps, stutter free, in a major hub such as KSEA or KLAX?Piccies would be gratefully welcomed. Here's hoping you can help. Thanks in advance.Michael H