I Have an HP Pavilion P7-1203 with 8gb RAM 1TB Hard Drive and I just upgraded from an i3 to the i5 2400(3.1Ghz), normal graphics to a GeForce GT 520 and from a 330W power supply to a 750W power supply. Also I just ordered the nVidia GeForce GTX 650Ti to put in it.
Now my question is, will upgrading all this stuff bottleneck my computer?
No problem. The i5-2400 is beefy enough for faster cards than the GTX 650ti. And if your asking, graphic cards don't bottleneck CPUs. It's the other way around. You are good. But, assuming it's of good quality, the 750W PSU is overkill for the 650ti. But it is always better to have too much than not enough.