$2000 buys overkill on the desktop.
However, I think that if you bought a modest, $700 or $800 PC, and a nice 20" LCD, that you'd be just as happy as if you blew the whole two grand.
Something like a Venice core a64/3200
Gigabyte 939 board to taste
1GB RAM
200GB Samsung Hard disk ($89 at newegg...