Wait I made a mistake. I was looking at i7 4790k, which you can't overclock a i7 4790 so scratch that part out (depends on the mobo, but not by much). But it will still give better performance than the i5.
Edit:
I suggest you ask the shop you're getting this at for an advice too. If he's truthful and not just trying to sell you expensive parts he'll give you personal experience knowledge.