And why can't you get a better card with my build?
No offensive snake, but there are some problems with your build.
First, an H55 board isn't good for gaming. It's meant to be used for an i3 in an onboard graphics setup. A good P55 board will cost much more.
Second, Thermaltake isn't exactly known for quality PSUs. Some of their units are alright, but many of them aren't. I doubt this one is one of the good ones, as it's not even 80% efficient.
Third, that RAM is a lot slower than the ones I linked to (CL 9 vs. CL 7). They will get worse once you start overclocking.
Sure, it may have an i5 in it. However, you sacrificied a lot of critical parts to get it and still weren't under budget. Keep in mind that the AM3 socket is much more future proof than the LGA1156, as the AM3 will have 6 core CPUs and the LGA1156 will not (looking years down the road as an upgrade).