GPU: If you want to spend that kind of money for a GPU, get the EVGA GTX 670 FTW. It performs better at the same price point.
PSU: I will avoid Cooler Master PSU's. They put labels in them that does not best represent its capabilities. Also, you only need a 550W PSU if you are not SLI'ing or xFire'ing. I suggest xfx core edition 550W.
The rest of your choices are good.
Try looking at these websites too and see if the parts you listed are cheaper: directcanada.com and bestdirect.ca. Both those websites will give you free shipping for orders over $50.
No need to change in any way (including my previous suggestions of course).
I noticed you didn't list what RAM you were going to buy. I would suggest 8 Gb (2 x 4 Gb) of DDR3 1600 1.5V RAM. Something like the G-Skill Ripjaws or Mushkin Blacklyne Frostbyte. If you have either one of those two, it should not interfere with the CPU cooler installation.
For RAM placements, check your MoBo manual. It is usually slots 1 and 3 (again, check the manual).
No, you don't need two. If you plan to go past that, you may need a better CPU cooler. Something like the Noctua NH-D14.
Test Bed: i7 3770k + Intel all in one liquid cooler
In their test bed, they were able to reach a stable overclock of 4.4 GHz at 1.05V which is close to the base. Temps are not going crazy then.
However, when they added voltage, once you get to 1.2V, temps are getting dangerously close to the 90 degree mark.
Also considering that different chips will OC differently, I think I will be uncomfortable with just the EVO. It might be just me though.
Guru3D uses the following games in their test suite: Hard Reset, COD-MW2, Far Cry 2, ANNO 1404, Metro 2033, ANNO 2070, BFBC2, BF3, Crysis 2, AvP, Lost Planet 2. Total fps (summing fps in each game @ 1920 x 1200) for the various options in parenthesis (single card / SL or CF) are tabulated below along with their cost in dollars per frame single card - CF or SLI:
In the table above for example, the Asus 670 Cu DCII TOP costs $430 each and gets 999 fps in single card configuration at a cost of $0.43 per frame and 1679 in SLI at a cost of $0.51 per frame. The AMD cards w/ NA did not complete all games in the test suite. This should be resolved in an upcoming driver fix. The nVidia card w/ NA was not tested in SLI.
The 7950 has some decent overclocking headroom, but no where near enough to catch the 670 TOP. Here's a comparison of the Asus 670 TOP and the 7970 TOP (Big brother to the 7950)
consumer' SSDs come in three flash flavors. Starting on the low end, you have IMFT 25nm asynchronous flash, a budget flash used in the Agility 3, Force 3, Chronos (non-Deluxe model) and a few other drives that in our testing perform at around the same level as last year's SF-1200 controlled drives when filled to 50 percent capacity. A majority of drives use IMFT 25nm synchronous flash; Vertex 3, Force GT, S511 and so on.
Synchronous flash, also called ONFi 2.x is really the first step for enthusiasts, especially now that prices have really dropped. The final flash type used is 3Xnm Toggle Mode flash from Toshiba, a form of ONFi 2.x without the JEDEC classification. 25nm IMFT is rated for around 5K P/E cycles and 3Xnm Toshiba Toggle Mode flash is rated for around twice as many. Even though we are talking about writing a lot of data for a very long time, the 3Xnm flash will still last even longer.