Hey,
consider the newer i7 2600k maybe? much more overclock-ability there but then your motherboard would need to change, so up to you, but they are also much more efficient.
As much as the two 570's will outperform one 580, one 580 will not hold you back at all, it is the roughly same price as two 570's, probably less, and will allow you to upgrade to a beast 580 sli later on when it's needed, or can be afforded. So consider adaptability.
can't complain about the ram, and also, if you can spare the money, maybe consider a small SSD for OS, and applications, and the 1TB or 2TB for data. The SSD will show unreal performance, and considering you have a SATA3 6gb/s mobo, consider taking advantage of that.
Although that is always an upgrade path later on when it is more affordable for you. But boot time and such will improve drastically.
So yeh, remember to check compatibility and looking good.