Thanks for all the help guys!!
I've changed my mind - again.
My original plan was to go wth studio monitors and after finding out that my local Guitar Center is having a weekend sale on studio monitors, I'm probably going to be coming home with some Behringers, KRK's or Mackies. We will see and I will keep this thread updated incase otherwise. Anyway, I'm going to still be needing the wires (which I have no clue which ones I'll need) and a subwoofer (but that can wait).
Like it says above, if anyone could help me figuring out which cables I'd need, that'd be greatttt.
What monitors did you end up getting, if any, and what kinds of outputs does your computer have?
Regarding the sub, there were (are?) a few Pinnacle sets on Woot right now, including one of their isobaric units (Babyboomer or Supersonic, I forget which). Otherwise I'd hop on Amazon and grab something like the Polk PSW505 or Bic F12 - probably more bass than any computer needs, but hey, you said loud. (This will be your whole budget though; if you had more, you'd get even nuttier suggestions ).