Need help if u know something about computers

Hey guys, my birthday is coming up and i thought i'd treat myself to a new graphics card. I know this isn't the greatest place to ask this type of stuff but I just have a few questions.

So first off my pc model is the hp p6610f, here is a link to my specs: http://support.hp.com/us-en/document/c02479651 Im looking at the EVGA GeForce GTX 750 ti and i wanted to know if my pci slots will hold the card. My PSU will be upgraded to that's out of the picture, and the 750 ti says it is backward compatible but i just wanted to make sure it will fit in to my pci slot. Another question is will having an older pci slot bottleneck the performance? If so an estimated amount would be a great help (severely, not much, a lot, etc.) One final question is, will getting the superclocked version increase my performance or will it be the same as the regular 750 ti since i don't have the pci 3.0. If you have any recommendations for a different card that will give a solid fps please share. I'm trying to keep the budget around $100-$170.

So basically my questions are: Will it fit? Will it perform? Which one do i buy?

Anything helps, thanks guys!