Like tiny voices said, the Coolermaster PSU is near-junk. Depending on the games and resolution, you might find a GDDR5 version of the HD6670 acceptable, but I'd strongly suggest something better. A HD7770 is only $115 now. In between those two lies the HD7750.
Also, I know you want cheap, but I'd also suggest a better mobo, like http://www.newegg.com/Product/Product.aspx?Item=N82E168... in order to get USB3.0 and SATA 6Gb/s. There's a $10 off promo code on it right now too.