make sure your motherboard has 3 spaces between each pcie slot so that your video cards wont get hot when you get sli/crossfire. another thing I would consider is getting xfx video cards. they offer double lifetime warranties on their stuff so if you ever resell it, it'll make it resell value higher. one more thing, I would get a full tower case instead of a mid tower. nzxt has a new case coming out that is really nice for 139 dollars.
Since you're up in Canada, I'd definitely try out NCIX.com for prices. The i5-760 is $199, and things are generally cheaper. You can also pricematch any other Canadian website like newegg or bestdirect.ca (which also has nice prices + free shipping always).
Secondly, if I were you, I'd swap out that video card right away! You can save $100 and get very similar performance with a nice GTX 460 1gb card. For $1200 or $1300 you could even fit two 460s in your budget, which would be a huge upgrade.
The best 460 is arguable, but the Palit Sonic OC one, and the Galaxy Super OC one have some of the best performance results out so far. They both run at 800mhz (the stock is 675mhz). Personally though, I'd buy the EVGA OC one here: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
SLI is pretty easy to do, you basically just plug them in, and change one setting in the nVidia control panel (it gives you the option to configure one as a PhysX only card... or do use them for SLI, etc.). There should be a few guides / forum questions on that too.
I finally decided to go only with 1 GTX 460 1GB OC and we'll see in the future (2-3 months) for another one. For the case, I think I'll stick with the CoolerMaster HAF922. BTW, I need suggestion for a monitor (full hd, max 23 in)
@sinhoyin - 460 SLI = QUITE a bit cheaper than 5870 CF. These cards are $200-225, while the 5870s where I live are $410+. So, $450 for an SLI setup that competes with a $820 crossfire setup... Still a tough choice?
@uness06 - Yep, you've got PLENTY of space in that HAF case of yours. And yeah, you can always add a second one in later! I bought two monitors in the past while, one is a 23" LG, the other a 24" BenQ. Here are those links. I prefer the picture of the LG to be honest.