First of all, I know I went $42 over, but that is to fit a 120GB SSD in there. You don't want to get an SSD smaller than 120/128GB; the price-scaling is terrible, and the size will only make you mad when you get it. The Samsung 840 is a fantastic SSD and is relatively cheap.
The Seagate Baracuda series of HDDs has about a 30% failure rate - that is too much for me. I recommend the Seagate SV35.5 series - they're pretty much just as cheap, but they are more reliable. I have a 2TB SV35.5 and it is both fast (for a HDD) and works well - I've been writing and reading 10GB+ every day for the past 6 months with no hiccups.
The Corsair CX series of PSUs are something I would avoid at all costs, if you can; low efficiency, poor manufacturing quality, and non-modular. Instead, I would grab the much better, albeit more expensive, Seasonic G 550. 550W is plenty for your system, plus, it is 80+ Gold, and "mostly" modular, or semi-modular, which is a real plus when cable management is an issue.
The Corsair 300R is a solid case with great cable management for the price; the air flow is acceptable, and the build quality is enough for the price. Corsair has a pretty good RMA service, as well, so any problems can easily be fixed.
The M5A99X Pro is nominally better than the Evo for a little less; they're essentially the same, though. Solid board, for the price.
Now, the biggest change is that I replaced the 660 with an AMD 7870 XT. The 7870XT is essentially a 7930, and is only a little bit weaker than the 7950. The 660, as with most Nvidia chips, are just overpriced for the power. Sure, they're great, and I even have one, but they aren't the best out there (the Titan aside) - you can get more GPU power from the AMD chips for the same price.