get yourself a big power supply, pay for quality and make sure its at least 700w. Dont ignore this one, as it feeds your system. Dont try to fill a swimming pool with a drinking straw is the analogy.
hard drive is just storage, seek times and rpm make some difference, but forget a drive for anything but an electronic bucket until solid state drives get to hundreds of Gb for a few dollars. I can get a terrabyte drive here for about $60, so its just beer money really.
AMD, Intel, meh. Theres always a price / performance trade off until it becomes obviously stupid to pay hundreds more for so very little. I like Intel, always have. Im sure AMD is just fine, and sometimes cheaper. Your budget will dictate your choices...
RAM = good. 8 Gb is plenty. You could cut back to 4Gb and still have things running well.
Make enquiries about dual video cards. You may get more out of a dual card system for somewhat cheaper than a single big card, plenty of tuning sites out there to get exact specs. The video card setup will likely be your biggest advantage with this sim, to get the jaw dropping goodies it will be able to dish up
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theres a site call tomshardware ive used for years, over a decade, never done me wrong. And NO im NOT affiliated. Just has good bar graph charts for simple comparisons.
VIDEO CARD. DUAL. GO ! NOW !