As for the HyperX... If you decide to take it, go for the Cloud 1, they say it sounds better.
Cloud 1 and Cloud 2 use the same drivers, so the sound is identical. The only difference is that Cloud 2 is more expensive, because you get extra useless accessories.
Kingston HyperX Cloud is a good choice. It's one of the rare gaming headsets that don't suck. The only problems with those headphones are: small soundstage and susceptible to damage microphone.
I recommend ISK HD9999 - just like HyperX very comfortable, V-shaped sound (highs and lows at the expense of mids - favors treble and bass, but a little bit worse with midrange, which mainly consists of vocals), quite big soundstage for closed construction (expansive to the sides), but a little bit too much bass because of thick pads. Generally the sound is bright and warm. The biggest advantage is that you can plug it in to everything and it will still sound awesome. The headphones offer quite good tolerance or rather ignorance to unfavorable source conditions. You don't need any soundcards or other professional DAC's.
You can also think about cheaper Encore Rockmaster OE. Comparing to ISK HD9999, it sounds less detailed, but also less aggressive (doesn't offer so much details into your face). It's more musical, soundstage is deeper (expansive forward and backward). The only problem is in treble - darker and weak in classical music.
As a microphone, cheap Zalman ZM-MIC1 should be enough for games.