If you do plan on overclocking, I didn't list an after market heatsink because I already went over the budget of $800, sadly (you can downgrade the case if you need to hit $800 or less to something like this.)
When you get the money, or if your aunt is willing to pay for all of it, get the Cooler Master Hyper 212 EVO.
Also, thermal paste will come pre-applied to the stock heat sink (bundled with the CPU), and the Hyper 212 EVO comes with a tube of it to apply yourself.
Hyper 212 EVO at the time of posting: $32.99
nvm but is there better graphic card but keep the i5?
btw need parts from amazon outletpc tigerdirect or any other pc store that accept international credit card. newegg dosent support international credit card
Yes the 660Ti is definitely worth it. However, as Stevenom stated: it won't be possible to get 50fps on Ultra settings with a $800 build. I'd wait and gather some more money before creating or a build, or be satisfied with what you have now.
I have a pretty good gaming computer right now. I'm using AMD(tm)-6350 6-Core Processor which has 3.9GHz.
And my video card is the GeForce GTX 650 Ti.
And 8 gigs of ram. Though I forgot my motherboard name. But those are some really good parts, cheap also.