Welcome to the forum!
I cannot find any reference to either a Lionel or Williams Rio Prospector set. I believe K-Line made one.
The Lionel number you reference is an Erie Lackawanna PA-1 locomotive set.

Any trains by any manufacturer can be operated on the Fastrack from Lionel. Larger locomotives and cars may need larger radius curves, however. The 80 watt basic transformer will power the train, but it would be wise to upgrade to a larger transformer to handle dual motor locomotives and to power accessories.

Larry