SSD
well.. if thats your choice
WD 600GB HDD
as far as i know wd uses 2 platters and samsung uses a single, less platters more reliable, the fact that it costs 250 dollars is fucking laughable id be seriously disgusted with you if you bought it
pcie 2.0 x 16 (x2)
not as important as you might think, id be more interested in extra phases but i think gigabyte is the right route
case
ft02 is the best case on the market, seriously
i really like the psu you picked out, gold rating will save you money and seasonic means its super reliable but 850 probably wont cut it, even if it works you have no overhead for overclocking anything