Not bad, there are just a couple things you need to change.
First, I would definitely get the newer i5 3570k over the i7 2500k. They are the same price, the 3570k has a slightly higher clockspeed than the 2500k and will beat the 2500k clock-for clock (ie, it would be faster even at the same clock speed) It also uses 77w compared to 95w on the 2500k, making it much more efficient. It also has an unlocked multiplier for overclocking, and the newer HD 4000 IGP from Intel and it supports PCIe 3.0
Intel Core i5-3570K Ivy Bridge 3.4GHz (3.8GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I53570K
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116504
Second, DO NOT get a Z68 motherboard. Z77 is better in every way, is better for overclocking and has been made for the latest ivy bridge (support for usb 3.0 and PCIe 3.0, etc..). The motherboard you listed isn't even on Newegg anymore, it has been discontnued as it is now obsolete... I have never used AsRock before, so I have nothing bad to say about them from my own experience, but i will say I haven't heard great things about them and I know there arer better manufacturers.. I would strongly recommend getting a motherboard from Asus.. Also, this motherboard supports LucidLogix GPU switching technology, which means you can run on the IGP until you run a graphically intensive program that requires the discrete GPU, which saves more power.
ASUS SABERTOOTH Z77 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131821
For the GPU, you can't go wrong with the card you selected. Me personally, i would go with an equivalent priced Nvidia GPU, but that is only because I'm an Nvidia fanboy, since most would agree that the 7950 is a better card with better overclocking capabilities..
SAPPHIRE FleX 100352FLEX-2 Radeon HD 7950 3GB 384-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card OC with Boost
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202007
For the Cpu cooler, yes you could cut some costs by going with a cheaper one, but I wouldn't if you plan on overclocking.. That being said, the h100 is massive, and you would be more likely to run into problems fittingit into a mid tower case, and a push/pull setup would be out of the question... I would definitely go with the h80i, it comes with a double thick radiator with push/pull fans out of the box, will stil fit better because it is not double-wide, and will give you lower temps than the h100, all wthout being significantly louder.. basically, h100i > h80i > h100 > h80.
CORSAIR Hydro Series H80i Water Cooler
http://www.newegg.com/Product/Product.aspx?Item=N82E16835181031
For the power supply, you again made an awesome choice! you can't go wrong with that power supply. However, right now you can save 20 bucks on the newer TX 750 v2, which has equivalent or better specs, just with 80+ Bronze certification instead.. many would argue that it is worth it to spend the extra bucks for the higher certification, me personally I wouldnt really care, it's not like you would notice a difference in your power bill and it's not like a power supply from corsair is going to die sooner because it only has a bronze certification, they are all good quality..
CORSAIR Enthusiast Series TX750 V2 750W ATX12V v2.31/ EPS12V v2.92 80 PLUS BRONZE Certified Active PFC High Performance Power Supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139021
Again, Great choice on the RAM.. I have never used G-skill, so I would go with the Corsair.. Also, i would advise getting the low profile.. Giant cheap heatsinks on RAM are pretty much just for looks, and are more likely to get in the way of something..
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233186
For cases, ether one you choose would be great! I would go for the 500r, since i don't really think a full tower is necessary when a mid would fit everything you need just fine, and you could save a bit of money... So of the two, i would definitely go with the 500r, me personally i would go with the Vengeance c70.
Corsair Vengeance Series C70 Arctic White Steel ATX Mid Tower Computer Case
http://www.newegg.com/Product/Product.aspx?Item=N82E16811139014
I didn't even know seagate made SSDs... I would again get the latest and greatest Corsair..
Corsair Neutron Series GTX CSSD-N120GBGTX-BK 2.5" 120GB SATA III Internal Solid State Drive (SSD)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233342
And for the hard drive
Western Digital WD Blue WD5000AAKX 500GB 7200 RPM 16MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136769
CONCLUSION: The above parts are what I would get. Most of them are just my own preference, and the ones you picked would be fine, WITH THE EXCEPTION OF THE CPU/MOTHERBOARD.. Like i said, there is absolutely no reason to pick a 2500k and Z68 motherboard.
Also, when you are looking for help with a new build, it would be much easier for people to help if we know wher you plan on buying the parts, your budget range, what is and isn't required, etc...
http://www.tomshardware.com/forum/353572-31-build-upgrade-advice