Thigs Id change:
-Secondary HDD fro hitachi or Samsung (seagates are probably the least reliable HDDS in the market).
-Power Supply: at least 650W but a good brand! DOnt get crappy PSUs. PSU fo PC is what the Engine is for a car.
-Headset: I probably wouldnt get that one, but thats is personal preference (Id go for sennheiser PC 350/360).
-Keyboard: Probably a mechanical keyboard, Steelseries 6Gv2 for RTS, Corsair Vengance K90 for FPS/racing (note that K90 is quite bad for writing).
Rest seems quite good.