Where is HDD? You got one already? Because i only see SSD in your build.
Yeah I agree - 120GB won't get you very far. You need a mechanical HD for this build, you can always get an SSD later.
That original build is an excellent start - the i5-3470 is only a $5 difference for higher clock speeds. And then for actually $50 less the Radeon 7950 is a better GPU than the 660TI is.
Sentey cases are overpriced junk - you would be wise to stay away from them. Get an NZXT Phantom 410 instead: http://www.newegg.com/Product/Product.aspx?Item=N82E16811146087
Also if you want an SSD this would be a better choice: http://www.newegg.com/Product/Product.aspx?Item=N82E16820147163
If you make those changes you'll save $70 easily and then you can add a nice 1TB mechanical HD to that build.