One of the first things I want to point out is that I didnt have the 3000 dollars and went to make just one purchase of all of this, if I had that money at hand I know I could go with something more balance, I´ve been buying everything has money comes, so at the end i´ve been spending 3k dollars in like 2 years.
Well this has been like a 1-2 year work, so I haven´t get all the parts in one purchase I´ve been buying everything has money comes, I use this computer basically for gaming but I also use it for programing, I have a 42" tv next to my rig so I also use it to watch movies and if the game have the approach to be play with a controller I play in my tv, sometimes also I play with my mouse and keyboard I have a table where I can put them, I recommend that for people who want to play on the tv (a table like that, I will post some picture too).
I go for the 7870 for my Full HD monitor last year, I think this card works great for this resolution, maybe you will need to quit AA for some games, but I been playing everything max out, even crysis 3, this year I was thinking to get a R9 290x but I think i would be a waste of money have been use for less than a year the 7870, so I think it would be better just to crossfire it, and I continue to play at Full HD so I think this upgrade would be useful for next gen game at this resolution, and now I can play Crysis 3 with AA max. And also I can see that this configuration performs better than the 7970 and 680 so is no that bad: http://www.youtube.com/watch?v=BMaSdtPIm08
I went for the Corsair AX1200i meanly thinking in a future proof, and because next year Im planing been playing at 4k so I will need some energy hehe, this build is using like 450w while gaming, I can monitor it with the corsair link software, so you can have an idea, I its at 95-99% of efficiency idle and gaming, I really recommend the AXi series
Im planning maybe next year get an 4k tv, so Ill be wating for next gen GPU´s that would be more improve for 4k gaming.
About the sound blaster zx, well to be true is the first sound card I´ve ever been bought, so I can only compare with inboard sound and obviously is way better, it sounds great with both, the headsets and the home theater, I think is a well balance card for gaming, music and movies, I and like that in any kind of products, were you have the flexibility to do more than just one think.
About the Cooler Master Seidon 240m, I come from using a cooler master TPC 812 air cooler, and well definitely water cooling is way better, with air I just manage to overclock my CPU to 4.0ghz at like 80c, next year also Im planning to go for custom water cooling.
And now talking about the cooler master cosmos 2, well I think is a good case, you can store whatever you want, but now that Im planing to go for custom water cooling I found some issues with this case, and well the mainly is that the top mounting is too short to put a thick radiator, and this really disappoints me, because is not a cheap case and they´re selling it like a great water cooling solution, but Im looking for radiator like the XSPC AX360 that some of the reviews I´ve been looking says that despite the size, it does a great job cooling with low RPM fans.