The seats are very similar to A-body seats, I seem to recall there may be a slight difference in the frame. Nothing that would keep you from using the seats themselves in your Duster, but maybe something to pay attention to for the reproduction covers.
The seat tracks for the B body will not work with the A-body mounting locations, you will need A-body bucket seat tracks (but those should fit the seat frames just fine).
I have no idea if the 6 way function can be changed over to the A-body seat track sliders, but I don't believe that was ever an option for the A-bodies. Could be wrong, not an original option expert.