ATI Radeon graphics (open source drivers), Sound Blaster Live. Spend the extra moolah to get a PostScript printer, and even get it networked if possible.

If the Radeon graphics card seems to be pricey (given that you're not a gamer), then the NVidia GeForce2 will, for not much dosh, give you spanky 2D performance and if you can be bothered with the binary drivers, ripping 3D, too. The NVidia drivers are packaged for Debian by the way. I have a GeForce2 MX. Paid less than a pony for it.

As for CPU & Board, I still kick ass with my PIII 800 and Abit BE6-II. Rock steady, but probably difficult to buy and the fastest processor I can use is 1GHz. Given that CPU speed isn't all that important, lay out a few extra sheets to get a decent mobo, and then slap a 1.3 Athlon on it or something.

As for monitors, Iiyama make nice monitors for reasonably small amounts of the folding stuff, and I've seen a few nice Belinea ones just lately, too.