There isn't much difference between the two, bottom line. Assuming you haven't bough the rest yet, ram mobo etc i would suggest going i7 8700 8th gen system instead.
Hyperthreading isn't a sure thing with lot of games, it may help in some games but often a margin so small not worth mentioning, just focus on the main cores.
If you want a cpu for the future go a 6 core minimum (8700). 4 cores are already a minimum for some games like Farcry 4 and GTA5 to either actually run or to perform.