That's a cool little case! Yes, the H100i is overkill. BUT, consider that one day you may upgrade your CPU and need better cooling, especially sticking with AMD. So is it overkill now? Yes. Will it be if you upgrade next year? Well..... Again, the H80 is also very strong.
I'd go H105 instead of H100i ever day too. Main diff is the H100i supports Corsairlink software, but my experiences with that software have been miserable and its super buggy. Reviews all over will indicate it seems to work better with some mobos than others for whatever reason. I just rely on the motherboards' fan controller to adjust fan speed as needed, based on CPU temps.