If you want to make sure your rig lasts for a long time, you should go I7.
In your case it's either I7 or I5 and everything else is the same anyway. I5 is good now, BUT it's just that and we don't know what future holds, however let me say this - in Battlefield 4 there is a healthy difference between I5 and I7 and this game is only the first of many to come.
Eventually you will upgrade CPU again - with I7 that eventually will come one year later, which is a good investment, in my opinion.