Ditto on what Cranked said, you understand the 875K is a 1st Gen Core (pre Sandy/Ivy Bridge) It costs as much as a Sandy/Ivy and its not going to perform quite as well.
Also, I wouldn't get a 64GB SSD as your primary boot drive, I wouldn't take anything below 120GB, as Windows is going to take a good 15GB of that, plus in NTFS format you'll lose about another 4 or 5GB. Doesn't leave much room for data/games etc.
For gaming, absolutely no advantage whatsoever of the i7 over the i5. No game on the market uses hyperthreading, and almost certainly NEVER will. Moornix has you on the right track, so I won't rehash what hes linking you.