My friend I wish I had good news for you. don't waste your money on expensive DDR RAM (I looked into getting some for another system and DDR runs close to DDR3 prices!

). And that CPU will never be able to provide what you're looking for, and neither will the integrated graphics.
You need to spend some money now and build yourself an FSX system if you want anything close to what this sim has to offer (and the awesome UTX/GEXn/FEX addons). Or you could wait for Nahelem at the end of the year. It's a tough spot to be in right now because if you spend now, it'll be just about obsolete at the end of the year (even though you'll have fun flying until then).
I would be
very happy to help you spend your money to build a nice FSX rig!
-Jim