This gives you a more powerful graphics card along with a quality case and psu. Quality power supplies are important.
As for the cpu, I wouldnt get it if you aren't going to overclock. If you are going to overclock you will also need to pay $30 more for a cpu cooler. Even if you overclock I dont know how high the cpu could go. You might be more interested with a Amd Phenom II 720 which is $20 cheaper and at a higher stock speed. Someone else can probably help you with the cpu better than I can.
I'd seriously consider going with AMD at your budget and with your uses. This combo deal has the AMD PhenomII x4 940 BE 3.0 GHz processor and a Biostar 790GX motherboard deal for $210.... $190 after rebate http://www.newegg.com/Product/ComboDealDetails.aspx?Ite...
You'd get much better performance and save a good chunk of cash. I'd also go with the Antec power supply and graphic card change that Hamit offered.