Help me buy a computer (PC)

This computer will be used for:
-3D modeling in AutoCAD, Inventor, and possibly Revvit in the future.
-Editing my HDV footage, nothing real fancy just some titles, transitions, etc...

I would like to have a dedicated video card, at least 4 gb of ram, CD/DVD+RW, Blue ray would be nice but I dont think I can afford it, an Intel or AMD dual core processor with at least 2.0 ghz. Hard drive size isnt super important but I would like the speed to be 7200 RPM

Screen size isnt super important as this will mainly be used at home and I have a monitor, keyboard, and mouse.

I would like to spend $800 or less on this.

So far this is my favorite pick but its still a little more than I would like to spend.

http://www.dell.com/us/en/home/notebooks/laptop_studio_17/pd.aspx?refid=laptop_studio_17&s=dhs&cs=19&~oid=us~en~29~studio_great_deals_anav_3~~

Any help would be greatly appreciated.