I dont really like hearing the term "Bottleneck". Your system will ALWAYS have a Bottleneck, be it the HDD, CPU, GPU Etc.
If you have the money, go ahead and buy a GTX 650TI Boost, or GTX 660. Might as well. Its going to be better no matter what.
And If you decide to upgrade your platform later, you will have a good video card. Not buying a cheaper card then having to upgrade the Platform and the Video card again in the future.