Fuck Husky, haven't I taught you anything?? 
Build it. 
When you do, make sure that you get an ATI Radeon 5970 for a video card.  Core i7 is a necessity too. Assuming you have 5k, RAID in SSDs wouldn't be a bad idea either.  
Also, in addition to the help you get here, you really should also post here to get some advice. 
I'll come back later with a full build, busy as fuck at the moment. 
And BTW, getting a higher level Core i7 is a HUGE waste of money. For $280 you can overclock the i7-920 to beyond the level of the $1,000 Core i7 975. 
Either go for the Core i7 920 or the Core i7 860. 
Step by Step Guide on how to build a PC. 
EDIT: That PC Steam put on here looks very good.  
BTW, no offense, but epic fail on the Dell.