the XP box is basically the only choice here, it has (in most cases) stability on its side, myself and some friends ran an XP pro box as a server and gateway for the net as well on an old p-2 box with a pile of RAM, it ran like a dog but it was just a stand alone server, sometimes network authentication and IP addy assignmetn was slow but thats coz of the slow computer, never gave us any really bad problems either