Athearn and Weaver 2-rail delrin (engineering plastic) wheelsets with steel axles drop right into MTH trucks. Atlas 2-rail wheelsets are double insulated. I have a large stash of used Athearn wheelsets. They are slightly dirty and some have been painted, but other than that OK. I am asking 25 cents an axle but am open.
Gargraves used to make (maybe still does make) a 2 rail track that is hirail height. It used the same rails as their 3-rail, but has only two and does not have the groove in the center of the tie for the 3 rail track.