The 431 Plus for $5 extra, comes with a front USB 3.0 port
No sense getting an unlocked CPU with an H77 motherboard - you forfeit access to the multiplier. If you're going to go H77 it's better to pair it with a 3450, but there's no real reason to get anything beyond that unless you're going to overclock.
The HAF 912 has better airflow and lots of nice extras than the Elite 431 does - I'd stick with it. The original build looks good to me, there really isn't a lot I would change.
Hey G-Unit, please check his processor link before posting. He linked a non-K 3570 with a Z77. I just changed that to a H77 and asked him to keep the non-K CPU in his link. Or the K with Z77
What on earth are you going on about?
What I'm saying is that it makes absolutely no sense to not get the 3570K if you're going to be paying that much money for a processor. With H77 you forfeit use of the multiplier. And the .1GHz speed differences between the 3450, 3550, and 3570 aren't that noticeable to warrant the extra cost. If you're going to overclock, do it. If not then you don't need a CPU with speeds that high. Put that money in the GPU instead. That's where the differences in a gaming build lie - not the CPU.