I like to build my own stuff, & it sounds like you can easily handle the assemble of a few components. BUT, if you have any doubts, you should know that there are alternatives. Not as good a performer as what you proposed, but simple, functional, new, warranty, and should last until you're out of school easily.
My wife just bought an eMachine (ewwww).
2.6Gig Celeron,
256Megs of ram,
80 Gig HD,
CD-RW,
DVD player,
17" Monitor,
printer,
& all the matching periferals (mouse, keyboard, speakers).
Cost her $800 bucks or so, then she got a bunch of rebates & the whole setup net cost under $450 with Windows XP Home & a bunch of other software installed. Plug N Play.
Now on your setup, I would suggest a 17" monitor will be fine for school - and they can be had for relatively little these days. Hell I bought a 19" for my youngest for $128 at Brandsmart. Use part of the difference to buy XP Pro, you get a nice discount.
