Hey SpongeBob. If your debating bang-for-buck with the whole AMD vs Intel, and NVidia vs ATI thing, then check out some benchmarking sites like the following for a rough guide:
http://www.cpubenchmark.net/high_end_cpus.htmlhttp://www.videocardbenchmark.net/high_end_gpus.htmlFor example you'll see the "1035T" PassMark score is a fair chunk less than "1090T" that Doug mentions and for not a great deal more price wise. If you decide on Intel and the i5/2500 definately go for the K model over the standard 2500, has a better overclocking potential for one thing if you decide to tinker later on, and its not much more expensive (I've just built a rig using the 2500K and am very happy with it)
Win7 (64bit version) is the way to go for FSX, and you'll be sweet with 8GB of RAM. GPU wise there are SO many options out there its pretty hard to reccomend one card/chip-set, but the one you list there does seem to be lagging a little performance wise considering whats on offer nowadays, I'd put a little more money towards that if I were you.