I'd go with the first one. The more powerful GPU will have more weight than the better CPU in the second build.
You can also upgrade it for drastically less than the other system; DDR3 can generally be found quite cheap, and an i7 from that era should be quite cheap as well. Really, if you're playing at 1080p60, the first build is likely going to give you a better experience.
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8GB of RAM is fine. It only becomes an issue if he is streaming while gaming and has a bunch of other apps open at the same time, which honestly if he's looking to buy those systems is unlikely.
Eh, they're about the same....or, you can upgrade to a 4690k, 4790k, etc for much less than it'd cost to upgrade a newer CPU.
The performance is about the same with a one or two generation gap once you factor in overclocking.