Hi Yshi -
Gaming ... gaming ... ok, let me offer a few thoughts for your consideration. I hope that these won't be redundant with what you've already researched
Not all games are equally intensive. Check out
http://www.systemrequirementslab.com - this site has an almost exhaustive list of games along with the minimum and recommended specs that your system will need. (By the way, I'm playing the new Batman on my "old" i920 with just a bit of overclock and a new EVGA GEForce GTX 760. I'm quite happy with the performance.)
Each month Toms publishes a set of articles on price/performance for both graphics and CPUs. You might find these articles interesting. Here's a link to the most current:
http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106.html
http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107.html
I see you're planning both a 250GB SSD and a 3TB HD. Why so much space? If this is primarily gaming then, as a reference, I currently have 8 games installed. I'm only actively playing three of them. In total they consume less than 100GB. Windows plus the standard utilities (anti-virus, Flash, Java, Silverlight, Acrobat, driver software, etc.) plus a full MS Office installation is going to run 30 to 40 GB. Plus 100GB for games, and your 250GB SSD should be plenty. If you're going to be keeping lots of videos, music, pictures and large files, then maybe the 3TB drive makes sense. Have you considered how you'll backup your system?
For the optical drive, you state simply "...external drive." Give some consideration to exactly how you're going to attach this. You'll want either eSata or USB3. USB2 will feel excruciatingly slow.
I don't see a card reader in your list. Don't know if this is important or not, but wanted to mention it.
If you haven't already, do a bit of research on how best to integrate an SSD into an overall build. There's lots of options out there, and depending on what's important to you may change your mind on the parts you buy. (E.g., just built a simple home PC for my parents, who are retired. I used the Intel SRT (SSD Caching) to provide some speed bonus for a standard HDD. It's a seamless and simple solution for Dad while keeping the price down with only a small SSD. Personally, I have a 128GB SSD for my system disk, and I have a 60GB SSD where I keep my temp files, log files, pagefile, etc., along with other standard HDD. It's a bit more complicated setup as I have to manage where I install applications, etc., but the family like the speed and performance.)
With an SSD, you'll also want to make decisions about what you do with SuperFetch, Prefetch, swap space, indexing, hibernation, etc.
I'm a big fan of modular PSU's. They cost a bit more, but it's nice not to have all the extra wires floating around in your case. The Antec 620-Modular HCG is also Bronze 80+ certified, so it's efficient in its power conversion. Hit Google with "psu configurator" and you'll get a number of sites that help you to make sure that you're sizing correctly for your power demands. I like to oversize and have a bit more power than I need.
The Noctua NH-D14 is a monster cooler, to be sure. You will want to be sure that it will fit into your case. I can't advise on this, as I'm not familiar with the specific sizings. The CPU you have above, Intel i5 4670K, runs at 3.4GHz with turbo up to 3.8Ghz as stock, out of the box. How much overclocking do you plan to do, and have you checked into some of the forums suggesting how much additional heat sink you'll need?
The Intel i5 4670K is a 4-core, 4-thread CPU. This will be more than sufficient for any gaming. If you're planning to do much video transcoding, you may want to consider the i7 with 4 cores and 8 threads. I think you will see a significant difference in the amount of time it takes to transcode a video between the i5/4/4 and the i7/4/8.
Lastly, jumping ahead a bit, google "breadboarding PC build." This is fancy terminology for assembling your PC components and getting all of them working *before* you screw them into the case. I find that I plug- and un-plug quite bit when building, and it's just so much easier when you don't have the casing constraints around the parts.
Yshi, I hope this has helped.
Good luck.