Actually it might work either way. We tried to do a digital filter but the sample interval was too long for the response time we wanted. (We were trying to balance the bridge). For your application a digital filter might work just fine. It depends on how fast you're moving. For the electronic filter I think it was just finding the right value of capacitor. I seem to remember alot of time spent with an oscilliscope and wavy lines and flat ones.
But I'm just an ME and they don't let me mess with wires too much. Something about letting the magic smoke out too often.
ChrisH
PS let me know if you run out of channels, sometimes this sort of thing takes months which you probably don't have.