As long as the i7 CPU is LGA1151 socket, it will do, e.g i7-6700.
Note: If you buy a K-series CPU then you can't OC (overclock) it since build uses B-series MoBo. For CPU OC, you need a Z-series MoBo.
2nd note about K-series CPUs: you also need to buy a CPU cooler since K-series CPUs don't come with Intel's stock cooler.
As far as PSU goes, Seasonic is the best there is. They are the 1st PC PSU OEM in the world and thanks to this, they have over 40 years of experience.
They make PSUs for such popular companies as Antec, Be Quiet!, Cooler Master, Corsair, EVGA, Silverstone, XFX. While also selling their own PSUs aswell.
But if you buy a low quality PSU (
like this one) then there's a high chance it will fry your entire PC.