Well, you certainly have got more money than I thought from your first post.  And the commitment to go for the best.

Congrats on getting a 4 CPU board, Windows 2003 Server and on planning to get 4 Opterons.  That's more than I could ever afford.  When you get the system up and running, let us know your VUE score and how the system runs.

Boxed fans should be fine.  Those opterons are tested for stability at max loads, much more so than the consumer CPUs since they are an 'enteprise' class product.  I'd pay a little more and have a quality shop assemble the system for you - the parts you are getting are too pricey to take a chance at screwing something up.

I, for one, will be very envious.  Enjoy the journey.