do a search for rm-x2s... there's a really good girder plugin written for it around here somewhere. it is much easier to interface it to the joystick port than serial, as the software is already available for it.
only problem with the rm-x2s is there seems to be some resistance change with temperature change. i've found on some cold mornings it doesn't work too well til the cabin has warmed up.
i have my rmx2s connected up to the game port of a cheap $17 soundcard.