[POLL] Intel core i5 or Intel core i7 for this custom PC

The difference between an i5 and i7, in terms of utilising your graphics card is effectively zero. i7 has hyperthreading, but no games use that, so they are both effectively the same for gaming.
In fact, very little software uses hyperthreading. The one common software type that does is high-end photographic software. If you are using something like Adobe CS6, then it can be worth getting i7. Otherwise, forget it. It's just a waste of money.

Get a better psu than that xfx 550w. Its not a horrible psu but there are better ones out there and only 550w would limit your future upgrades

The only drawback of the XFX is that it's not modular, but the quality is very good, it's made by Seasonic!

Here's a list of the cahnges i made to your build in order to make it as close to perfect as possible.

1st : that motherboard is known to have VRM overheating issues.
2nd : i replaced the graphics card with one made by Sapphire.It's cooler is vastly superior to the one made by XFX.
3rd: i switched the ram with a low voltage kit made by Mushkin which is known to overclock well.
4th: i upgraded the case to a Corsair Carbide 300R which has superior quality.
5th: i upgraded the Optical Drive
6th: i added a much better power supply which is much more efficient and provides enough power for two of those graphics cards.It even features a modular cabling system which will dramaticly reduce the amount of floating cables in your case.
7th : i replaced the hard drive with one made by Western Digital.In my experiance they are much, much more reliable and don't cost a lot more.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($27.98 @ NCIX US)
Motherboard: Gigabyte GA-Z77X-UD3H ATX LGA1155 Motherboard ($149.98 @ NCIX US)
Memory: Mushkin Blackline 8GB (2 x 4GB) DDR3-1600 Memory ($39.99 @ Newegg)
Storage: Samsung 830 Series 128GB 2.5" Solid State Disk ($89.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($74.99 @ NCIX US)
Video Card: Sapphire Radeon HD 7970 3GB Video Card ($387.86 @ Newegg)
Case: Corsair 300R ATX Mid Tower Case ($72.35 @ Amazon)
Power Supply: Rosewill Capstone 750W 80 PLUS Gold Certified ATX12V / EPS12V Power Supply ($99.99 @ Newegg)
Optical Drive: Lite-On iHAS224-06 DVD/CD Writer ($19.99 @ SuperBiiz)
Total: $1153.11
(Prices include shipping, taxes, and discounts when available.)

wow, I really appreciate the time you put into the response. I will look into it as soon as I get home!

THANKS!

Hey, I had someone suggest this video card http://www.newegg.com/Product/Product.aspx?Item=N82E168...

what do you think about using that one? Is it worth the money?

The GTX670 is a good GPU. It's not as powerful, over a broad range of games, as the 7970 GHz, although it does score particularly well in some of the most popular games, that tend to be optimised for nVidia, like BF3, Shogun, Portal, the new Borderlands.
I wouldn't however, necessarily, choose that one. Asus have got a couple of good versions, and the Gigabyte Windrush, was chosen, by Toms, as the best version, overall.

i5 anyday, you only need and i7 if doing professional stuff like video editing. The GTX670 is the most you would need for gaming. but the 7970 isn't bad either.

Stick with the i5, the i7 isn't really worth the price unless it's the 6-core which is total overkill except for a workstation.