Budget Range: $1000-1500 After Rebates; obviously cheaper is better
System Usage from Most to Least Important: Gaming, CAD, Video editing
Parts Not Required: keyboard, mouse, speakers
Preferred Website(s) for Parts: newegg, tigerdirect, amazon, etc... any reputable source with the cheapest part
Country of Origin: USA
SLI or Crossfire: Eventually in a future upgrade
Monitor Resolution: tbd, but most likely 1920x1080
Additional Comments: Looking for pure performance at a decent value. Looks and name brands don't matter. Minimal power consumption would be nice, but is not a requirement. I am also considering upgrading to a SSD at some point, but right now they are out of my price range.
Video Card: This is where I need the most help. I don't want to spend more than ~400. As far as gaming, if I can run games on medium to medium-high settings, I will be happy. Video editing and CAD shouldn't be too intense, but I want to be able to render a moderately complex model if necessary.
Looking over your 950 configuration, you've selected some very good parts.
If your gaming needs are moderate as you describe (1920 resolution or less, and willing to compromise settings on some games to avoid $$$), you really needn't go for the i7 950. An i5 750 will be a strong performer for you, saving money, power, heat, and perhaps cooling fan noise vs the 950.
Here's a sample i5 750 configuration to check out. It uses a different version of the case you selected, an equal quality but appropriately lower power psu, and some parts you chose:
You have a good list of parts.
To answer some of your issues:
1) The corsair 850 is a good unit, but probably stronger than you will ever need. As an alternative, how about the XFX750?
It is a bit cheaper after rebate, it is modular, and silver certified. It will run any single graphics card out there, and most in sli/crossfire.
2) It is wise to wait a bit on the SSD. I love them, they make everything feel much snappier. Gen 3 units are due out soon, and should be bigger, vaster, and cheaper. Plan ahead by using AHCI and setting aside a suitably sized partition on your 1tb drive.
4) With a high end cpu, and an interest in gaming, get a good graphics card. I suggest a GTX460 1gb model. It will do very well at 1920 x 1200. It also scales very well in SLI if you should ever need more. It is less than your $400 budget, but should serve you well for modest gaming. I like the external exhaust models http://www.newegg.com/Product/Product.aspx?Item=N82E168...
5) Get a 1920 x 1200 monitor instead of a 1080P(1920 x 1080) monitor. Look at the viewing angle, 178/178 is the best, 160/160 is what you will see for cheaper units. Most monitors are decent, I like Samsung, they make the panels for many others, and I think they keep the best samples for themselves.
6) Download and read, cover to cover the motherboard and case manuals.
7) The i5-750 approach that twoboxer mentioned is also a viable one, but I would go with more than 4gb of ram if possible.
A quality 650W will suffice for 2x460, since running (Furmark) max graphics will only draw 480W at the wall, ~430 from your psu. Add a cushion for also running driving your cpu hard, as in a game, and you still are operating at under 80% of the 650's capacity.
There's nothing wrong with using a 750W - its just not the first place to allocate money if funds are limited.
Don't let anybody talk you out of the bigger PSU. The bigger the better. One of the worst mistakes (and most often made) any DIY can make is overworking the PSU. The bigger PSU will pay you dividends you'll never know about.
I know the i5-750 is really all I need, but I'm having difficulty turning down the i7-950 for the additional $100 since I have the money and it has been 5+ years now since my last new build.
The GTX460 seems to be what I am looking for and definitely fits the budget with the option to upgrade in SLI later.
One benefit of a i7-950 based system is the superior triple channel ram capability. Not so much for the speed, as the ease of using 6gb which is a sweet spot for ram capacity in general. You might even consider using 3 x 4gb(12gb) as your starting ram for video editing. There is not much of a price premium for 4gb sticks.
One question on the PSU though, will a 650 be fine if I do eventually go SLI on the 460, or would the 750 be the safer option?
The XFX unit I referenced earlier has 62a on the 12v lines, and 4 pci-e connectors. More than enough for two GTX460 cards. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Actually the XFX650w unit would be enough, but for only $10 more after rebate, I like the silver efficiency certification, and a few more amps capability.