2000 was the last year of that generation Ranger and a couple of things changed. I know Tom can tell you a little about that since he has a 2000. I think they went from selectable (pulse vacuum I think) to full time front hubs in 2000, and there are some other differences as well but that's the biggest one I remember.
Mostly, there is no difference in them for most of the models. I think the Trailhead, the EDGE 4x2 predecessor, came out that year as well and it's different in having the 4x4 suspension on a 4x2, but that doesn't affect you.