PC Build for CAD applications $1200 budget

Hey, I've been wanting to build a new machine for a while, I have finally saved up a decent amount, and I need the computer for school starting in January. I've learned a lot about all the components and what the specs mean so far, but my main concern is I don't want to over spend on high-end components I don't really need.

APPROXIMATE PURCHASE DATE: early next month.

BUDGET RANGE: $1200 CAD, or approximately 1000 USD.

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: 3d Modelling, AutoDesk products (Max, Revit, CAD), Secondary uses - gaming, Movies.

PARTS NOT REQUIRED: Keyboard, mouse, speakers, sound card, modem.

PREFERRED WEBSITE(S) FOR PARTS: www.tigerdirect.ca, www.newegg.ca, anywhere that ships to Canada(southern Ontario) for a reasonable price.

PARTS PREFERENCES: I've been leaning towards Intel products but whatever gets the best performance within my price range will be fine.

OVERCLOCKING: I don't know anything about over clocking but I am certainly willing to learn.
SLI OR CROSSFIRE: Same as overclocking.

MONITOR RESOLUTION: (e.g.: 1024x768, 1280x1024,)

ADDITIONAL COMMENTS:

I have one LCD monitor(VGA, 15") but I would like to have dual monitors So i'll need a new one, at least 17", Doesn't have to be DVI compatible.

As for the case I really like the sleek look of the Apevia X-DREAMER3 Mid Tower Case.

Obviously I want to keep it as cool and quite as possible.

Thanks a lot in advance.