I can only think of kits, that you would build yourself, don't know if that would help.
Verlinden has fountain sets, and Armand Bayardi used to make resin kits of fountains, in his catalog of diorama pieces. But you'd have to assemble and paint them, and supply the water effect (eg, Woodland Scenics, or other various clear resins or epoxies).
I'm sure some of the finished figure collectors will know more about ready-to-display pieces.
I'm also thinking now of our favorite hunting ground, Michael's. Not sure, but some of the miniature lines they carry may have something, probably a little more finished-looking, like a Victorian town fountain or something similar.
Prost!
Brad