Yes the i5 is plenty good, but the point of the PSU is quality level not wattage. you can only determine quality by pretty much reading reviews from people with multi-thousand dollar tools for testing.
That psu again is fine, but if you want long term then you could do the GQ or GS as both are top rated units.
550 will last you just fine. But 650 will be a little more ideal as it would allow you to overclock anything in the future easily, and you ideally want to be using about 50-75% of your PSU's total wattage at max load.
This post was edited by Rapture on Jun 25 2016 12:38am