Also, no point getting a 7.1 sound card and put 2.0 speaker on it.
For gaming, W7 HP will be good enough.
Also, please format your part list next time (this time I did it for you). It was difficult to know what you are buying if you copy and paste what you had from newegg without any sort of format (big gaps between parts in the list and strings of numbers which we don't need).
If you can bump up your budget a bit and you would over clock then i suggest an intel i5 2500k but if not overclocking a i5 2400 or if you can't bump up your budget an i3 cpu like the 2100 would work better as well for gaming.